U.S. patent application number 13/388111 was filed with the patent office on 2012-05-24 for organic electroluminescence device.
This patent application is currently assigned to FUJIFILM CORPORATION. Invention is credited to Toshihiro Ise, Tetsu Kitamura, Akira Takeda, Keiju Tonosaki, Toru Watanabe.
Application Number | 20120126692 13/388111 |
Document ID | / |
Family ID | 42330908 |
Filed Date | 2012-05-24 |
United States Patent
Application |
20120126692 |
Kind Code |
A1 |
Ise; Toshihiro ; et
al. |
May 24, 2012 |
ORGANIC ELECTROLUMINESCENCE DEVICE
Abstract
An organic electroluminescence device which has on a substrate a
pair of electrodes and a light emitting layer sandwiched between
the electrodes, characterized by containing in the light emitting
layer a compound represented by the following formula (1) and a
particular indium complex; (Cz).sub.p-L-(A).sub.q (1) wherein Cz
represents a substituted or unsubstituted arylcarbazolyl group or a
substituted or unsubstituted carbazolylaryl group, L represents a
single bond, a substituted or unsubstituted arylene group, a
substituted or unsubstituted cycloalkylene group, or a group
derived from a substituted or unsubstituted heteroaromatic ring, A
represents a group derived from a substituted or unsubstituted
nitrogen-containing heteroaromatic 6-membered ring, and each of p
and q independently represents an integer from 1 to 6.
Inventors: |
Ise; Toshihiro; (Kanagawa,
JP) ; Kitamura; Tetsu; (Kanagawa, JP) ;
Watanabe; Toru; (Kanagawa, JP) ; Takeda; Akira;
(Kanagawa, JP) ; Tonosaki; Keiju; (Kanagawa,
JP) |
Assignee: |
FUJIFILM CORPORATION
Tokyo
JP
|
Family ID: |
42330908 |
Appl. No.: |
13/388111 |
Filed: |
July 28, 2010 |
PCT Filed: |
July 28, 2010 |
PCT NO: |
PCT/JP2010/063132 |
371 Date: |
January 31, 2012 |
Current U.S.
Class: |
313/504 ;
252/301.16 |
Current CPC
Class: |
C09K 11/06 20130101;
C09K 2211/1011 20130101; C09K 2211/1088 20130101; H01L 51/0085
20130101; C09K 2211/1029 20130101; H05B 33/14 20130101; H01L
51/5016 20130101; H01L 51/0067 20130101; H01L 51/0072 20130101;
C09K 2211/185 20130101; C09K 2211/1092 20130101; C09K 2211/1007
20130101 |
Class at
Publication: |
313/504 ;
252/301.16 |
International
Class: |
H05B 33/14 20060101
H05B033/14; C09K 11/06 20060101 C09K011/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2009 |
JP |
2009-180224 |
Sep 25, 2009 |
JP |
2009-221665 |
Claims
1.-15. (canceled)
16. An organic electroluminescence device, comprising on a
substrate: a pair of electrodes; and a light emitting layer
sandwiched between the electrodes, wherein the light emitting layer
contains a compound represented by the following formula (3) and a
compound represented by the following formula (T-2): ##STR00067##
wherein each of X.sub.4 and X.sub.5 independently represents a
nitrogen atom or a carbon atom, and a ring containing X.sub.4 and
X.sub.5 is a pyridine or a pyrimidine; L' represents a single bond
or a phenylene group; each of R.sup.1 to R.sup.5 independently
represents a fluorine atom, a methyl group, a phenyl group, a cyano
group, a pyridyl group, a pyrimidyl group, a silyl group, a
carbazolyl group, or tert-butyl group; each of n1 to n5
independently represents an integer of 0 or 1; and each of p' and
q' independently represents an integer of 1 or 2, and ##STR00068##
wherein R.sub.3' represents an alkyl group; each of R.sub.4' to
R.sub.6' independently represents a hydrogen atom, an alkyl group,
an alkenyl group, a heteroalkyl group, an aryl group or a
heteroaryl group; R.sub.5' and R.sub.6' may combine with each other
to from an aryl ring; R.sub.5 represents an aryl group or a
heteroaryl group, which each may further have a nonaromatic group,
the nonaromatic group is an alkyl group, an alkoxy group, a fluoro
group, a cyano group, an alkylamino group, or diarylamino group;
each of R.sub.3, R.sub.4 and R.sub.6 independently represents a
hydrogen atom or an alkyl group; the heteroalkyl group represents a
group in which at least one carbon in an alkyl group is replaced
with O, --NR--, or S, and R represents a hydrogen atom, an alkyl
group, an alkenyl group, an alkynyl group, a heteroalkyl group, an
aryl group, or a heteroaryl group; (X--Y) represents an
acetylacetonate or a picolinate; and m represents an integer of 2
and n represents an integer of 1.
17. The organic electroluminescence device according to claim 16,
wherein the ring containing X.sub.4 and X.sub.5 is a
pyrimidine.
18. The organic electroluminescence device according to claim 16,
wherein the compound represented by the formula (T-2) is a compound
represented by the following formula (T-3): ##STR00069## wherein
R.sub.4' independently represents a hydrogen atom, an alkyl group,
an alkenyl group, a heteroalkyl group, an aryl group or a
heteroaryl group; R.sub.5'' and R.sub.6'' represent hydrogen atoms
or combine with each other to form an aryl ring; each of R.sub.3,
R.sub.4 and R.sub.6 independently represents a hydrogen atom or an
alkyl group; the heteroalkyl group represents a group in which at
least one carbon in an alkyl group is replaced with O, --NR--, or
S, and R represents a hydrogen atom, an alkyl group, an alkenyl
group, an alkynyl group, a heteroalkyl group, an aryl group, or a
heteroaryl group; (X--Y) represents an acetylacetonate or a
picolinate; and m represents an integer of 2 and n represents an
integer of 1.
19. The organic electroluminescence device according to claim 18,
wherein the compound represented by the formula (T-3) is a compound
represented by the following formula (T-4): ##STR00070## wherein
each of R.sub.3, R.sub.4 and R.sub.6 independently represents a
hydrogen atom or an alkyl group; (X--Y) represents an
acetylacetonate or a picolinate; and m represents an integer of 2
and n represents an integer of 1.
20. The organic electroluminescence device according to claim 18,
wherein R.sub.4' in the formula (T-2) or (T-3) represents a
hydrogen atom, an alkyl group, an aryl group, or a fluoro
group.
21. The organic electroluminescence device according to claim 16,
wherein R.sub.5' and R.sub.6' in the formula (T-2) represents a
hydrogen atom or combine with each other to form an aryl ring.
22. A composition comprising: a compound represented by the formula
(3); and a compound represented by the formula (T-2), which are
recited in claim 16.
23. A light emitting layer comprising: a compound represented by
the formula (3); and a compound represented by the formula (T-2),
which are recited in claim 16.
24. A film formation method, wherein a compound represented by the
formula (3) and a compound represented by the formula (T-2), which
are recited in claim 16, are made to sublime by simultaneous
heating to form a film.
25. A light luminous apparatus comprising the organic
electroluminescence device according to claim 16.
26. A display apparatus comprising the organic electroluminescence
device according to claim 16.
27. An illumination apparatus comprising the organic
electroluminescence device according to claim 16.
Description
TECHNICAL FIELD
[0001] The present invention relates to an organic
electroluminescence device (hereinafter, referred to also as "a
device" or "an organic EL device"), and more specifically, an
organic electroluminescence device which is excellent in durability
at high luminance intensity.
BACKGROUND ART
[0002] Research and development of organic electroluminescence
devices has been actively conducted in recent years because highly
luminescent luminous is obtained from these devices with
low-voltage driving. In general, organic electroluminescence
devices are constituted of an organic layer including a
light-emitting layer, and a pair of electrodes between which the
organic layer is sandwiched, and electrons injected from the
cathode are recombined with holes injected from the anode in the
light-emitting layer, to produce excitons, whose energy is utilized
to luminescence.
[0003] Improvement in the efficiency of devices has recently made
by using a phosphorescent materials. For instance, WO 05/085387
discloses the organic electroluminescence device whose luminous
efficiency and heat resistance are enhanced by using an iridium
complex, a platinum complex or the like as a phosphorescent
material.
[0004] On the other hand, doped devices using light-emitting layers
whose host materials are doped with light-emitting materials are
widely adopted.
[0005] Development of host materials also has been actively made.
JP-A-2009-99783, for example, discloses the invention using
condensed aromatic polycyclic materials as the host materials to
form devices of high efficiency and long life. However, such an
invention is insufficient in luminous efficiency and durability
with high-temperature driving, and what is more, in the case of
considering the uses for display and illumination, such an
invention has a problem that shifts in chromaticity are caused as
the devices are driven. Improvements in those points are therefore
required.
[0006] As described in JP-A-2009-99783, it is known that the use of
materials which can produce an unstable oxidized species having
carbazolyl groups is unfavorable to durability of devices. In light
of such common knowledge, embodiments of the present invention
couldn't be expected to have effects on durability improvements. On
the other hand, in the phosphorescent materials of iridium complex
type, it is presumed that devices performance is degraded because
of decomposition occurred by leaving ligand, which often occurs in
complex-type materials, and production of quencher. Thus the
practical use of phosphorescent materials is known to involve
difficulties.
[0007] However, we have found that durability improvement effects
are produced by using host materials containing carbazolyl group
according to the invention in combination with specific materials
of iridium complex type.
[0008] Hitherto, a chromaticity shift accompanied to the driving of
a device as well as a rise in drive voltage and a reduction in
efficiency has been adopted as a point of evaluation. Further,
evaluations have been made at various ambient temperatures from
room temperature to high temperatures (mainly in the sense of an
acceleration test). However, no attention has been given to the
fact that the extent of the chromaticity shift was greater under
high-temperature drive than under low-temperature drive. In recent
years the range of uses for organic electroluminescence devices has
been extended e.g. to uses in displays and panels as well as uses
for an illumination purpose. When uses in car-mounted panels or the
like, which can get a high temperatures reach 80.degree. C. or
higher, are contemplated, it is predicted that the chromaticity
shift under high-temperature drive will become an important
problem.
SUMMARY OF INVENTION
[0009] An objective of the invention is to provide an organic
electroluminescence device which has excellent luminescence
characteristics, can suppress a chromaticity shift under
high-temperature drive and excel in luminous efficiency.
[0010] Another objective of the invention is to provide a
composition and a light emitting layer useful to such an organic
electroluminescence device. A further objective of the invention is
to provide a film formation method for the compound useful to such
an organic electroluminescence device. And still another objective
of the invention is to provide a light luminous apparatus and an
illumination apparatus each incorporating such an organic
electroluminescence device.
[0011] More specifically, the invention is achieved by the
following.
[1] An organic electroluminescence device which has on a substrate
a pair of electrodes and a light emitting layer sandwiched between
the electrodes, wherein the light emitting layer contains a
compound represented by the following formula (1) and a compound
represented by the following formula (T-1).
(Cz)p-L-(A)q (1)
[0012] In the formula (1), Cz represents a substituted or
unsubstituted arylcarbazolyl group or a substituted or
unsubstituted carbazolylaryl group, L represents a single bond, a
substituted or unsubstituted arylene group, a substituted or
unsubstituted cycloalkylene group, or a group derived from a
substituted or unsubstituted heteroaromatic ring, A represents a
group derived from a substituted or unsubstituted
nitrogen-containing heteroaromatic 6-membered ring, and each of p
and q independently represents an integer from 1 to 6.
##STR00001##
[0013] In the formula (T-1), R.sub.3' represents an alkyl group, a
heteroalkyl group, an aryl group or a heteroaryl group, which each
may further have a substituent Z; R.sub.5 represents an aryl group
or a heteroaryl group, which each may further have a nonaromatic
substituent; the ring Q represents an aromatic heterocyclic ring or
condensed aromatic heterocyclic ring which has at least one
nitrogen atom to form a coordination bond with Ir, and the ring Q
may further have a nonaromatic substituent; each of R.sub.3,
R.sub.4 and R.sub.6 independently represents a hydrogen atom, an
alkyl group, an alkenyl group, an alkynyl group, --CN, --CF.sub.3,
--C.sub.nF.sub.2n+1, a trifluorovinyl group, --CO.sub.2R, --C(O)R,
--NR.sub.2, --NO.sub.2, --OR, a halogen atom, an aryl group or a
heteroaryl group, which each may further have a substituent; or
R.sub.3 and R.sub.4 may combine with each other to complete a
condensed 4- to 7-membered ring, and the 4- to 7-membered ring is a
cycloalkane ring, a cycloheteroalkane ring, an arene ring or a
heteroarene ring, which each may further have a substituent Z; or
R.sub.3' and R.sub.6 may complete a ring by linking via a linking
group selected from the groups consisting of
--CR.sub.2--CR.sub.2--, --CR.dbd.CR--, --CR.sub.2--, --O--, --NR--,
--O--CR.sub.2--, --NR--CR.sub.2-- and --N.dbd.CR--, wherein each of
Rs independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group
or a heteroaryl group, which each may further have a substituent Z;
each of Zs independently represents a halogen atom, --R', --OR',
--N(R').sub.2, --SR', --C(O)R', --C(O)OR', --C(O)N(R').sub.2, --CN,
--NO.sub.2, --SO.sub.2, --SOR', --SO.sub.2R' or --SO.sub.3R', and
each of R's independently represents a hydrogen atom, an alkyl
group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a
heteroalkyl group, an aryl group or a heteroaryl group; (X--Y)
represents an ancillary ligand; m represents an integer from 1 to 3
and n represents an integer from 0 to 2, provided that m+n=3.
[2] The organic electroluminescence device according to [1],
[0014] wherein the compound represented by the formula (1) is a
compound represented by the following formula (2).
##STR00002##
[0015] In the formula (2), Cz represents a substituted or
unsubstituted arylcarbazolyl group or a substituted or
unsubstituted carbazolylaryl group; L represents a single bond, a
substituted or unsubstituted arylene group, a substituted or
unsubstituted cycloalkylene group, or a group derived from a
substituted or unsubstituted heteroaromatic ring, and L is linked
to the carbon atom in Ar.sub.1, Ar.sub.2, X.sub.1, X.sub.2 or
X.sub.3; each of Ar.sub.1 and Ar.sub.2 independently represents a
substituted or unsubstituted aryl group, a substituted or
unsubstituted arylene group, or a group derived from a substituted
or unsubstituted heteroaromatic ring; each of X.sub.1, X.sub.2 and
X.sub.3 independently represents a nitrogen atom or a carbon atom
which may have a substituent; and each of p and q independently
represents an integer from 1 to 6.
[3] The organic electroluminescence device according to [2],
[0016] wherein the compound represented by the formula (2) is a
compound represented by the following formula (3).
##STR00003##
[0017] In the formula (3), each of X.sub.4 and X.sub.5
independently represents a nitrogen atom or a carbon atom which may
have a substituent, provided that either X.sub.4 or X.sub.5
represents a nitrogen atom and the other represents a carbon atom
which may have a substituent; L' represents a single bond, a
substituted or unsubstituted arylene group, a substituted or
unsubstituted cycloalkylene group, or a group derived from a
substituted or unsubstituted heteroaromatic ring; each of R.sup.1
to R.sup.5 independently represents a substituent; each of n1 to n5
independently represents an integer from 0 to 5; and each of p' and
q' independently represents an integer from 1 to 4.
[4] The organic electroluminescence device according to any of [1]
to [3], wherein each of the ring from which the group represented
by A in the formula (1) is derived, the ring containing X.sub.1 to
X.sub.3 in the formula (2) and the ring containing X.sub.4 and
X.sub.5 in the formula (3) is pyridine or pyrimidine. [5] The
organic electroluminescence device according to any of [1] to
[3],
[0018] wherein each of the ring from which the group represented by
A in the formula (1) is derived, the ring containing X.sub.1 to
X.sub.3 in the formula (2) and the ring containing X.sub.4 and
X.sub.5 in the formula (3) is pyrimidine.
[6] The organic electroluminescence device according to any of [1]
to [5],
[0019] wherein the compound represented by the formula (T-1) is a
compound represented by the following formula (T-2).
##STR00004##
[0020] In the formula (T-2), R.sub.3' represents an alkyl group, a
heteroalkyl group, an aryl group or a heteroaryl group, which each
may further have a substituent Z; each of R.sub.4' to R.sub.6'
independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group
or a heteroaryl group, which each may further have a substituent Z;
or R.sub.3' and R.sub.4', or R.sub.4' and R.sub.5', or R.sub.5' and
R.sub.6' may combine with each other to complete a 4- to 7-membered
ring condensed with the pyridine ring, and the 4- to 7-membered
ring is a cycloalkane ring, a cycloheteroalkane ring, an arene ring
or a heteroarene ring, which each may further have a substituent Z;
or R.sub.3' and R.sub.6 may complete a ring by linking via a
linking group selected from the groups consisting of
--CR.sub.2--CR.sub.2--, --CR.dbd.CR--, --CR.sub.2--, --O--, --NR--,
--O--CR.sub.2--, --NR--CR.sub.2-- and --N.dbd.CR--, wherein each of
the R.sub.5 independently represents a hydrogen atom, an alkyl
group, an alkenyl group, an alkynyl group, a heteroalkyl group, an
aryl group or a heteroaryl group, which each may further have a
substituent Z; R.sub.5 represents an aryl group or a heteroaryl
group, which each may further have a nonaromatic group; each of
R.sub.3, R.sub.4 and R.sub.6 independently represents a hydrogen
atom, an alkyl group, an alkenyl group, an alkynyl group, --CN,
--CF.sub.3, --C.sub.nF.sub.2n+1, a trifluorovinyl group,
--CO.sub.2R, --C(O)R, --NR.sub.2, --NO.sub.2, --OR, a halogen atom,
an aryl group or a heteroaryl group, which each may further have a
substituent Z, or R.sub.3 and R.sub.4 may combine with each other
to complete a 4- to 7-membered ring condensed with the benzene
ring, and the 4- to 7-membered ring is a cycloalkane ring, a
cycloheteroalkane ring, an arene ring or a heteroarene ring, which
each may further have a substituent Z; each of Zs independently
represents a halogen atom, --R', --OR', --N(R').sub.2, --SR',
--C(O)R', --C(O)OR', --C(O)N(R').sub.2, --CN, --NO.sub.2,
--SO.sub.2, --SOR', --SO.sub.2R' or --SO.sub.3R', and each of R's
independently represents a hydrogen atom, an alkyl group, a
perhaloalkyl group, an alkenyl group, an alkynyl group, a
heteroalkyl group, an aryl group or a heteroaryl group; (X--Y)
represents an ancillary ligand; and m represents an integer from 1
to 3 and n represents an integer from 0 to 2, provided that
m+n=3.
[7] The organic electroluminescence device according to [6],
[0021] wherein the compound represented by the formula (T-2) is a
compound represented by the following formula (T-3).
##STR00005##
[0022] In the formula (T-3), R.sub.4' represents a hydrogen atom,
an alkyl group, an alkenyl group, an alkynyl group, a heteroalkyl
group, an aryl group or a heteroacryl group, which each may further
have a substituent Z; R.sub.5'' and R.sub.6'' represent hydrogen
atoms or combine with each other to complete a condensed 4- to
7-membered ring, and the condensed 4- to 7-membered ring is a
cycloalkane ring, a cycloheteroalkane ring, an arene ring or a
heteroarene ring; each of R.sub.3, R.sub.4 and R.sub.6
independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, --CN, --CF.sub.3,
--C.sub.nF.sub.2n+1, a trifluorovinyl group, --CO.sub.2R, --C(O)R,
--NR.sub.2, --NO.sub.2, --OR, a halogen atom, an aryl group or a
heteroaryl group, which each may further have a substituent Z; each
of Rs independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group
or a heteroaryl group, which each may further have a substituent Z;
or R.sub.3 and R.sub.4 may combine with each other to form a
condensed 4- to 7-membered ring, and the 4- to 7-membered ring is a
cycloalkane ring, a cycloheteroalkane ring, an arene ring or a
heteroarene ring, which each may have a substituent Z; each of Zs
independently represents a halogen atom, --R', --OR',
--N(R').sub.2, --SR', --C(O)R', --C(O)OR', --C(O)N(R').sub.2, --CN,
--NO.sub.2, --SO.sub.2, --SOR', --SO.sub.2R' or --SO.sub.3R', and
each of R's independently represents a hydrogen atom, an alkyl
group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a
heteroalkyl group, an aryl group or a heteroaryl group; (X--Y)
represents an ancillary ligand; and m represents an integer from 1
to 3 and n represents an integer from 0 to 2, provided that
m+n=3.
[8] The organic electroluminescence device according to [7],
[0023] wherein the compound represented by the formula (T-3) is a
compound represented by the following formula (T-4).
##STR00006##
[0024] In the formula (T-4), each of R.sub.3, R.sub.4 and R.sub.6
independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, --CN, --CF.sub.3,
--C.sub.nF.sub.2n+1, a trifluorovinyl group, --CO.sub.2R, --C(O)R,
--NR.sub.2, --NO.sub.2, --OR, a halogen atom, an aryl group or a
heteroaryl group, which each may further have a substituent Z; each
of Rs independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group
or a heteroaryl group, which each may further have a substituent Z;
each of Zs independently represents a halogen atom, --R', --OR',
--N(R').sub.2, --SR', --C(O)R', --C(O)OR', --C(O)N(R').sub.2, --CN,
--NO.sub.2, --SO.sub.2, --SOR', --SO.sub.2R' or --SO.sub.3R', and
each of R's independently represents a hydrogen atom, an alkyl
group, a perhaloalkyl group, an alkenyl group, an alkynyl group, a
heteroalkyl group, an aryl group or a heteroaryl group; (X--Y)
represents an ancillary ligand; and m represents an integer from 1
to 3 and n represents an integer from 0 to 2, provided that
m+n=3.
[9] The organic electroluminescence device according to any of [1]
to [8],
[0025] wherein the ancillary ligand (X--Y) is any of
acetylacetonate (acac), picolinate (pic), derivative of
acetylacetonate (acac) and derivative of picolinate (pic).
[10] A composition containing a compound represented by the formula
(1) and a compound represented by the formula (T-1), which are
described in [1]. [11] A light emitting layer containing a compound
represented by the formula (1) and a compound represented by the
formula (T-1), which are described in [1]. [12] A film formation
method,
[0026] wherein a compound represented by the formula (1) and a
compound represented by the formula (T-1), which are described in
[1], are made to sublime by simultaneous heating and formed into
film.
[13] A light luminous apparatus containing the organic
electroluminescence device according any of [1] to [9]. [14] A
display apparatus containing the organic electroluminescence device
according to any of [1] to [9]. [15] An illumination apparatus
containing the organic electroluminescence device according to any
of [1] to [9].
ADVANTAGE OF THE INVENTION
[0027] The organic electroluminescence devices according to the
invention have low power consumption, high external quantum
efficiency and excellent durability. In addition, they have small
shifts in chromaticity under high-temperature drive, and can
therefore deliver steady performance even in uses for which drive
durability in high-temperature conditions are required, such as an
automobile use.
BRIEF DESCRIPTION OF DRAWINGS
[0028] FIG. 1 is a schematic diagram showing an example of a layer
structure of the organic EL device relating to a first embodiment
of the invention.
[0029] FIG. 2 is a schematic diagram showing an example of light
luminous apparatus relating to a second embodiment of the
invention.
[0030] FIG. 3 is a schematic diagram showing an example of
illumination apparatus relating to a third embodiment of the
invention.
DESCRIPTION OF EMBODIMENTS
[0031] In illustration of the following formulae (1) to (3) and the
following formulae (T-1) to (T-4), the expression "hydrogen atom"
is intended to also include isotopes thereof (such as a deuterium
atom) and the expression "atoms", which constitute a substituent,
is intended to also include isotopes thereof.
[0032] In the invention, the expression "the number of carbon
atoms" in a substituent such as an alkyl group is used in the sense
that the substituent may further have other substituents and the
carbon atoms contained in the other substituents are also counted
as the carbon atoms of the substituent.
[0033] And the term "heteroalkyl group" refers to the alkyl group
at least one carbon atom of which is replaced with O, NR or S.
[0034] The present organic electroluminescence device contains a
pair of electrodes on a substrate, and a light emitting layer is
sandwiched between the pair of the electrodes, and the light
emitting layer contains a compound represented by the following
formula (1) and a compound represented by the following formula
(T-1)
[0035] The compound represented by the formula (1) is illustrated
below.
(Cz).sub.p-L-(A).sub.q (1)
[0036] In the formula (1), Cz represents a substituted or
unsubstituted arylcarbazolyl group or a substituted or
unsubstituted carbazolylaryl group, L represents a single bond, a
substituted or unsubstituted arylene group, a substituted or
unsubstituted cycloalkylene group, or a group derived from a
substituted or unsubstituted heteroaromatic ring, A represents a
group derived from a substituted or unsubstituted
nitrogen-containing heteroaromatic 6-membered ring, and each of p
and q independently represents an integer from 1 to 6.
[0037] The formula (1) is explained below in detail.
[0038] Cz represents a substituted or unsubstituted arylcarbazolyl
group or a substituted or unsubstituted carbazolylaryl group.
[0039] The aryl group in each of the arylcarbazolyl group and the
carbazolylaryl group is preferably from 6 to 30 in the number of
carbons, with examples including a phenyl group, a naphthyl group,
an anthryl group, a phenanthryl group, a naphthacenyl group, a
pyrenyl group, a fluorenyl group, a biphenyl group and a terphenyl
group. Of these groups, a phenyl group, a naphthyl group, a
biphenyl group and a terphenyl group are preferable, a phenyl group
and a biphenyl group are especially preferable.
[0040] The aryl group in each of the arylcarbazolyl group and the
carbazolylaryl group is not particularly restricted as to its
substitution position on the carbazole ring, but in terms of
chemical stability and carrier-transporting capability, it is
preferable that the aryl group substitutes for the hydrogen on the
2-position, 3-position, 6-position, 7-position or 9-position of the
carbazole ring, it is more preferable that the aryl group
substitutes for the hydrogen on the 3-position, 6-position and
9-position of the carbazole ring and it is the most preferable that
the aryl group substitutes for the hydrogen on the 9-position
(N-position) of the carbazole ring.
[0041] When Cz represents an arylcarbazolyl group, though there is
no particular restriction on the Cz-L linking, the arylcarbazolyl
group is preferably linked to L at the 2-position, 3-position,
6-position, 7-position or 9-position (N-position) of the carbazole
ring, far preferably linked to the L at the 3-position, 6-position,
or 9-position (N-position) of the carbazole, ring, especially
preferably linked to the L at the 9-position (N-position) of the
carbazole ring.
[0042] However, it is preferable that Cz is a carbazolylaryl
group.
[0043] A represents a group derived from a substituted or
unsubstituted nitrogen-containing heteroaromatic 6-membered ring,
preferably a group derived from a nitrogen-containing
heteroaromatic 6-membered ring in which the number of carbons is
from 2 to 40. The group represented by A may have two or more
substituents, and these substituents may combine with each other
and form a ring or rings.
[0044] Examples of a nitrogen-containing heteroaromatic 6-membered
ring or a nitrogen-containing heteroaromatic ring having a
nitrogen-containing heteroaromatic 6-membered ring include
pyridine, pyrimidine, pyrazine, pyridazine, triazine,
azaindolizine, indolizine, purine, pteridine, .beta.-carboline,
naphthyridine, quinoxaline, terpyridine, bipyridine, acridine,
phenanthroline, phenazine and imidazopyridine. Of these rings,
pyridine, pyrimidine, pyrazine and triazine are preferable,
pyridine and pyrimidine are far preferable, and pyrimidine is the
most preferable.
[0045] L represents a single bond, a substituted or unsubstituted
arylene group, a substituted or unsubstituted cycloalkylene group,
or a group derived from a substituted or unsubstituted
heteroaromatic ring.
[0046] The arylene group is preferably an arylene group in which
the number of carbon atoms is from 6 to 30, with examples including
a phenylene group, a biphenylene group, a terphenylene group, a
naphthylene group, an anthranylene group, a phenanthrylene group, a
pyrenylene group, a chrysenylene group, a fluoranthenylene group
and a perfluoroarylene group. Of these groups, a phenylene group, a
biphenylene group, a terphenylene group and a perfluoroarylene
group are preferable to the others, a phenylene group, a
biphenylene group and a terphenylene group are far preferable, and
a phenylene group and a biphenylene group are further
preferable.
[0047] The cycloalkylene group is preferably a cycloalkylene group
in which the number of carbon atoms is from 5 to 30, with examples
including a cyclopentylene group, a cyclohexylene group and a
cycloheptylene group. Of such groups, a cyclopentylene group and a
cyclohexylene group are preferable to the others, and a
cyclohexylene group is far preferable.
[0048] The group derived from a heteroaromatic ring is preferably a
group derived from a heteroaromatic ring in which the number of
carbon atoms is from 2 to 30, with examples including groups
derived respectively from a 1-pyrrolyl group, a 2-pyrrolyl group, a
3-pyrrolyl group, a pyrazinyl group, a 2-pyridinyl group, a
3-pyridinyl group, a 4-pyridinyl group, a 1-indolyl group, a
2-indolyl group, a 3-indolyl group, a 4-indolyl group, a 5-indolyl
group, a 6-indolyl group, a 7-indolyl group, a 1-isoindolyl group,
a 2-isoindolyl group, a 3-isoindolyl group, a 4-isoindolyl group, a
5-isoindolyl group, a 6-isoindolyl group, a 7-isoindolyl group, a
2-furyl group, a 3-furyl group, a 2-benzofuranyl group, a
3-benzofuranyl group, a 4-benzofuranyl group, a 5-benzofuranyl
group, a 6-benzofuranyl group, a 7-benzofuranyl group, a
1-isobenzofuranyl group, a 3-isobenzofuranyl group, a
4-isobenzofuranyl group, a 5-isobenzofuranyl group, a
6-isobenzofuranyl group, a 7-isobenzofuranyl group, a 2-quinolyl
group, a 3-quinolyl group, a 4-quinolyl group, a 5-quinolyl group,
a 6-quinolyl group, a 7-quinolyl group, an 8-quinolyl group, a
1-isoquinolyl group, a 3-isoquinolyl group, a 4-isoquinolyl group,
a 5-isoquinolyl group, a 6-isoquinolyl group, a 7-isoquinolyl
group, an 8-isoquinolyl group, a 2-quinoxalinyl group, a
5-quinoxalinyl group, a 6-quinoxalinyl group, a 1-carbazolyl group,
a 2-carbazolyl group, a 3-carbazolyl group, a 4-carbazolyl group, a
9-carbazolyl group, a 1-phenanthridinyl group, a 2-phenanthridinyl
group, a 3-phenanthridinyl group, a 4-phenanthridinyl group, a
6-phenanthridinyl group, a 7-phenanthridinyl group, an
8-phenanthridinyl group, a 9-phenanthridinyl group, a
10-phenanthridinyl group, a 1-acridinyl group, a 2-acridinyl group,
a 3-acridinyl group, a 4-acridinyl group, a 9-acridinyl group, a
1,7-phenanthroline-2-yl group, a 1,7-phenanthroline-3-yl group, a
1,7-phenanthroline-4-yl group, a 1,7-phenanthroline-5-yl group, a
1,7-phenanthroline-6-yl group, a 1,7-phenanthroline-8-yl group, a
1,7-phenanthroline-9-yl group, a 1,7-phenanthroline-10-yl group, a
1,8-phenanthroline-2-yl group, a 1,8-phenanthroline-3-yl group, a
1,8-phenanthroline-4-yl group, a 1,8-phenanthroline-5-yl group, a
1,8-phenanthroline-6-yl group, a 1,8-phenanthroline-7-yl group, a
1,8-phenanthroline-9-yl group, a 1,8-phenanthroline-10-yl group, a
1,9-phenanthroline-2-yl group, a 1,9-phenanthroline-3-yl group, a
1,9-phenanthroline-4-yl group, a 1,9-phenanthroline-5-yl group, a
1,9-phenanthroline-6-yl group, a 1,9-phenanthroline-7-yl group, a
1,9-phenanthroline-8-yl group, a 1,9-phenanthroline-10-yl group, a
1,10-phenanthroline-2-yl group, a 1,10-phenanthroline-3-yl group, a
1,10-phenanthroline-4-yl group, a 1,10-phenanthroline-5-yl group, a
2,9-phenanthroline-1-yl group, a 2,9-phenanthroline-3-yl group, a
2,9-phenanthroline-4-yl group, a 2,9-phenanthroline-5-yl group, a
2,9-phenanthroline-6-yl group, a 2,9-phenanthroline-7-yl group, a
2,9-phenanthroline-8-yl group, a 2,9-phenanthroline-10-yl group, a
2,8-phenanthroline-1-yl group, a 2,8-phenanthroline-3-yl group, a
2,8-phenanthroline-4-yl group, a 2,8-phenanthroline-5-yl group, a
2,8-phenanthroline-6-yl group, a 2,8-phenanthroline-7-yl group, a
2,8-phenanthroline-9-yl group, a 2,8-phenanthroline-10-yl group, a
2,7-phenanthroline-1-yl group, a 2,7-phenanthroline-3-yl group, a
2,7-phenanthroline-4-yl group, a 2,7-phenanthroline-5-yl group, a
2,7-phenanthroline-6-yl group, a 2,7-phenanthroline-8-yl group, a
2,7-phenanthroline-9-yl group, a 2,7-phenanthroline-10-yl group, a
1-phenazinyl group, a 2-phenazinyl group, a 1-phenothiazinyl group,
a 2-phenothiazinyl group, a 3-phenothiazinyl group, a
4-phenothiazinyl group, a 10-phenothiazinyl group, a 1-phenoxazinyl
group, a 2-phenoxazinyl group, a 3-phenoxazinyl group, a
4-phenoxazinyl group, a 10-phenoxazinyl group, a 2-oxazolyl group,
a 4-oxazolyl group, a 5-oxazolyl group, a 2-oxadiazolyl group, a
5-oxadiazolyl group, a 3-furazanyl group, a 2-thienyl group, a
3-thienyl group, a 2-methylpyrrole-1-yl group, a
2-methylpyrrole-3-yl group, a 2-methylpyrrole-4-yl group, a
2-methylpyrrole-5-yl group, a 3-methylpyrrole-1-yl group, a
3-methylpyrrole-2-yl group, a 3-methylpyrrole-4-yl group, a
3-methylpyrrole-5-yl group, a 2-t-butylpyrrole-4-yl group,
3-(2-phenylpropyl)pyrrole-1-yl group, a 2-methyl-1-indolyl group, a
4-methyl-1-indolyl group, a 2-methyl-3-indolyl group, a
4-methyl-3-indolyl group, a 2-t-butyl-1-indolyl group, a
4-t-butyl-1-indolyl group, a 2-t-butyl-3-indolyl group and a
4-t-butyl-3-indolyl group. Of these groups, the groups derived
respectively from a pyridinyl group, a quinolyl group, an indolyl
group and a carbazolyl group are preferable to the others, and the
groups derived respectively from a pyridinyl group and a carbazolyl
group are far preferable.
[0049] L stands for preferably a single bond, a phenylene group, a
biphenylene group, a cyclohexylene group, a pyridnylene group or a
carbazolylene group, far preferably a single bond, a phenylene
group or a biphenylene group, and further preferably a single bond
or a phenylene group.
[0050] Examples of a substituent each of the groups represented by
Cz and A in the formula (1) can include halogen atoms such as
fluorine, chlorine, bromine and iodine, a carbazolyl group, a
hydroxyl group, substituted or unsubstituted amino groups, a nitro
group, a cyano group, a silyl group, a trifluoromethyl group, a
carbonyl group, a carboxyl group, substituted or unsubstituted
alkyl groups, substituted or unsubstituted alkenyl groups,
substituted or unsubstituted arylalkyl groups, substituted or
unsubstituted aryl groups, substituted or unsubstituted aromatic
heterocyclic groups, substituted or unsubstituted aryloxy groups,
and substituted or unsubstituted alkyloxy groups. Of these
substituents, a fluorine atom, a methyl group, a perfluorophenylene
group, a phenyl group, a naphthyl group, a pyridyl group, a pyrazyl
group, a pyrimidyl group, an adamantyl group, a benzyl group, a
nitro group, a cyano group, a silyl group, a trifluoromethyl group,
a carbazolyl group and combinations of only these groups are
preferable, a fluorine atom, a methyl group, a phenyl group, a
pyridyl group, a pyrimidyl group, a cyano group, a silyl group, a
carbazolyl group and combinations of only these groups are far
preferable, a phenyl group, a pyridyl group, a pyrimidyl group, a
carbazolyl group and combinations of only these groups are further
preferable, and a phenyl group is the best. When the group
represented by Cz or A has two or more substituents, these
substituents may combine with each other and form a ring or
rings.
[0051] Each of p and q in the formula (1) independently represents
an integer from 1 to 6, preferably 1 to 4, far preferably 1 to 3,
and further preferably 1 or 2.
[0052] The compound represented by the formula (1) is preferably a
compound represented by the following formula (2).
##STR00007##
[0053] In the formula (2), Cz represents a substituted or
unsubstituted arylcarbazolyl group or a substituted or
unsubstituted carbazolylaryl group; L represents a single bond, a
substituted or unsubstituted arylene group, a substituted or
unsubstituted cycloalkylene group, or a group derived from a
substituted or unsubstituted heteroaromatic ring, and L is linked
to the carbon atom in Ar.sub.1, Ar.sub.2, X.sub.1, X.sub.2 or
X.sub.3; each of Ar.sub.1 and Ar.sub.2 independently represents a
substituted or unsubstituted aryl group, a substituted or
unsubstituted arylene group, or a group derived from a substituted
or unsubstituted heteroaromatic ring; each of X.sub.1, X.sub.2 and
X.sub.3 independently represents a nitrogen atom or a carbon atom
which may have a substituent; and each of p and q independently
represents an integer from 1 to 6.
[0054] The formula (2) is explained below in detail.
[0055] Definitions of Cz, L, p and q in the formula (2) are the
same as those in the formula (1), respectively, and preferable
examples of Cz, L, p and q in the formula (2) are also the same as
those in the formula (1).
[0056] Each of Ar.sub.1 and Ar.sub.2 independently represents a
substituted or unsubstituted aryl group, a substituted or
unsubstituted arylene group, or a group derived from a substituted
or unsubstituted heteroaromatic ring.
[0057] The aryl group is preferably a substituted or unsubstituted
aryl group in which the number of carbon atoms is from 6 to 30,
with examples including a phenyl group, a biphenyl group, a
terphenyl group, a naphthyl group, an anthranyl group, a
phenanthryl group, a pyrenyl group, a chrysenyl group, a
fluoranthenyl group and a perfluoroaryl group. Of these groups, a
phenyl group, a biphenyl group, a terphenyl group and a
perfluoroaryl group are preferably, a phenyl group, a biphenyl
group and a terphenyl group are far preferable, and a phenyl group
and a biphenyl group are further preferable.
[0058] The arylene group is preferably an arylene group in which
the number of carbon atoms is from 6 to 30, and examples thereof
and groups for which the arylene group has preferences are the same
as those recited in the explanation of L in the formula (1). And
the group derived from a heteroaromatic ring is preferably a
heteroaromatic ring which is substituted or unsubstituted group and
the number of carbon atoms is from 2 to 30, and examples thereof
and groups for which the group has preferences are the same as
those recited in the explanation of L in the formula (1). When
substituents are attached to those groups, examples of the
substituents and groups preferred as the substituents are the same
as those recited as the substituents of Cz and A in the formula
(1).
[0059] Each of the ring members X.sub.1, X.sub.2 and X.sub.3
independently represents a nitrogen atom or a carbon atom which may
have a substituent. Cases where at most two of X.sub.1, X.sub.2 and
X.sub.3 are nitrogen atoms are preferable, cases where none or one
of X.sub.1, X.sub.2 and X.sub.3 is a nitrogen atom are far
preferable, and cases where any one of X.sub.1, X.sub.2 and X.sub.3
is a nitrogen atom are the most preferable. When any one of
X.sub.1, X.sub.2 and X.sub.3 is a nitrogen atom, it is preferred
that either of X.sub.1 and X.sub.3 be a nitrogen atom. The ring
containing X.sub.1 to X.sub.3 in the formula (2) is preferably
pyridine or pyrimidine, far preferably pyrimidine. Examples of a
substituent which can be bonded to the carbon atom and groups
preferred as the substituent are the same as those recited as the
substituents of Cz and A in the formula (1). Additionally, the
linking position of L in the formula (2) has no particular
restriction but, in terms of chemical stability and
carrier-transporting capability, it is preferred that L be linked
to a Carbon atom in Ar.sub.1.
[0060] The compound represented by the formula (1) is far
preferably a compound represented by the following formula (3).
##STR00008##
[0061] In the formula (3), each of X.sub.4 and X.sub.5
independently represents a nitrogen atom or a carbon atom which may
have a substituent, it is preferable that either X.sub.4 or X.sub.5
represents a nitrogen atom and the other represents a carbon atom
which may have a substituent; L' represents a single bond, a
substituted or unsubstituted arylene group, a substituted or
unsubstituted cycloalkylene group, or a group derived from a
substituted or unsubstituted heteroaromatic ring; each of R.sup.1
to R.sup.5 independently represents a substituent; each of n1 to n5
independently represents an integer from 0 to 5; and each of p' and
q' independently represents an integer from 1 to 4.
[0062] The formula (3) is explained below in detail.
[0063] Each of X.sub.4 and X.sub.5 independently represents a
nitrogen atom or a carbon atom which may have a substituent.
Herein, it is preferable that either X.sub.4 or X.sub.5 represents
a nitrogen atom and the other represents a carbon atom which may
have a substituent.
[0064] In the formula (3), the ring containing X.sub.4 and X.sub.5
is preferably pyridine or pyrimidine, far preferably pyrimidine.
Examples of a substituent bonded to the carbon atom and groups
preferred as the substituent are the same as those recited as the
substituents of Cz and A in the formula (1).
[0065] The definition of L' in the formula (3) is the same as that
of L in the formula (1), and groups preferred as L' are the same as
those preferred as L. And L' is linked to a benzene ring in the
nitrogen-containing heteroaromatic ring structure drawn in the
formula (3).
[0066] Each of R.sup.1 to R.sup.5 independently represents a
substituent. Examples of the substituent and preferred substituent
are the same as those recited as the substituents of Cz and A in
the formula (1). When more than one R.sup.1, R.sup.2, R.sup.3,
R.sup.4 or R.sup.5 are present, each R.sup.1, R.sup.2, R.sup.3,
R.sup.4 or R.sup.5 may be the same as or different from every other
R', R.sup.2, R.sup.3, R.sup.4 or R.sup.5, respectively.
[0067] Each of n1 to n5 independently represents an integer from 0
to 5. And each is preferably 0, 1 or 2, far preferably 0 or 1,
further preferably 0.
[0068] Each of p' and q' independently represents an integer from 1
to 4. And each is preferably 1, 2 or 3, far preferably 1 or 2.
[0069] The compound represented by the formula (1) is most
preferably composed only of a carbon atom, a hydrogen atom, and a
nitrogen atom.
[0070] The molecular weight of the compound represented by the
formula (1) is preferably from 400 to 1,000, far preferably from
450 to 800, and further preferably from 500 to 700.
[0071] The lowest triplet excited state (T1) energy that the
compound represented by the formula (1) has in the form of film is
preferably from 2.61 eV (62 kcal/mol) to 3.51 eV (80 kcal/mol), far
preferably from 2.69 eV (63.5 kcal/mol) to 3.51 eV (80 kcal/mol),
further preferably from 2.76 eV (65 kcal/mol) to 3.51 eV (80
kcal/mol).
[0072] The glass transition temperature (Tg) of the compound
represented by the formula (1) is preferably from 80.degree. C. to
400.degree. C., far preferably from 100.degree. C. to 400.degree.
C., further preferably from 120.degree. C. to 400.degree. C.
[0073] Hydrogen atoms in the formula (1) may also include isotopic
atoms of hydrogen (such as deuterium atoms). In such a case, the
compound may be in a state that all the hydrogen atoms are replaced
with isotopic atoms of hydrogen, or it may be a mixture of the
compounds that have differing degrees of partial replacement of
hydrogen atoms with isotopic atoms of hydrogen.
[0074] Examples of the compound represented by the formula (1) are
illustrated below, but the invention should not be construed as
being limited to these examples. Additionally, Ph in the following
examples represents a phenyl group.
##STR00009## ##STR00010## ##STR00011## ##STR00012## ##STR00013##
##STR00014## ##STR00015## ##STR00016## ##STR00017## ##STR00018##
##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023##
##STR00024## ##STR00025## ##STR00026## ##STR00027## ##STR00028##
##STR00029## ##STR00030##
[0075] The above compounds which exemplify the compound represented
by the formula (1) can be synthesized according to various methods,
such as the methods disclosed in WO 03/080760, WO 03/078541 and WO
05/085387 brochures.
[0076] For example, the compound of Exemplified Compound 4 can be
synthesized using m-bromobenzaldehyde as a starting material in
accordance with the method disclosed in WO 05/085387 brochure (from
page 45, line 11, to page 46, line 18). The compound of Exemplified
Compound 45 can be synthesized using 3,5-dibromobenzaldehyde as a
starting material in accordance with the method disclosed in WO
03/080760 brochure, page 46, line 9 to line 12. In addition, the
compound of Exemplified Compound 68 can be synthesized using
N-phenylcarbazole as a starting material in accordance with the
method disclosed in WO 05/022962 brochure, page 137, line 10, to
page 139, line 9.
[0077] In the invention, the compound represented by the formula
(1) may be incorporated into any layer besides a light emitting
layer. Examples of a layer suitable for introduction of the
compound represented by the formula (1) include a light emitting
layer, a hole injection layer, a hole transporting layer, an
electron transporting layer, an electron injection layer, an
exciton blocking layer and a charge blocking layer. It is
preferable that the compound represented by the formula (1) may be
introduced into one or any one or more of those layers.
[0078] When the compound represented by the formula (1) is
incorporated into a light emitting layer, the compound content is
preferably from 0.1% to 99% by mass, far preferably from 1% to 95%
by mass, further preferably from 10% to 95% by mass, with respect
to the total mass of the light emitting layer. When the compound
represented by the formula (1) is further incorporated into a
certain layer other than the light emitting layer, the compound
content is preferably from 70% to 100% by mass, far preferably from
85% to 100% by mass.
<Compound Represented by Formula (T-1)>
[0079] The compound represented by formula (T-1) is illustrated
below.
##STR00031##
[0080] In the formula (T-1), R.sub.3' represents an alkyl group, a
heteroalkyl group, an aryl group or a heteroaryl group, which each
may further have a substituent Z.
[0081] R.sub.5 represents an aryl group or a heteroaryl group,
which each may further have a nonaromatic substituent.
[0082] The ring Q represents an aromatic heterocyclic ring or
condensed aromatic heterocyclic ring which has at least one
nitrogen atom to form a coordination bond with Ir, and the ring Q
may further have a nonaromatic substituent.
[0083] each of R.sub.3, R.sub.4 and R.sub.6 independently
represents a hydrogen atom, an alkyl group, an alkenyl group, an
alkynyl group, --CN, --CF.sub.3, --C.sub.nF.sub.2n+1, a
trifluorovinyl group, --CO.sub.2R, --C(O)R, --NR.sub.2, --NO.sub.2,
--OR, a halogen atom, an aryl group or a heteroaryl group, which
each may further have a substituent Z.
[0084] R.sub.3 and R.sub.4 may combine with each other to complete
a condensed 4- to 7-membered ring, and the condensed 4- to
7-membered ring is a cycloalkane ring, a cycloheteroalkane, an
arene or a heteroarene, which each may further have a substituent
Z.
[0085] R.sub.3' and R.sub.6 may complete a ring by linking via a
linking group selected from the groups consisting of
--CR.sub.2--CR.sub.2--, --CR.dbd.CR--, --CR.sub.2--, --O--, --NR--,
--O--CR.sub.2--, --NR--CR.sub.2-- and --N.dbd.CR--, each of R.sub.5
independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group
or a heteroaryl group, which each may further have a substituent
Z.
[0086] Each of Zs independently represents a halogen atom, --R',
--OR', --N(R').sub.2, --SR', --C(O)R', --C(O)OR',
--C(O)N(R').sub.2, --CN, --NO.sub.2, --SO.sub.2, --SOR',
--SO.sub.2R' or --SO.sub.3R', and each of R's independently
represents a hydrogen atom, an alkyl group, a perhaloalkyl group,
an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl
group or a heteroaryl group.
[0087] (X--Y) represents an ancillary ligand.
[0088] m represents an integer from 1 to 3 and n represents an
integer from 0 to 2, provided that m+n=3.
[0089] The compound represented by the formula (T-1) is a complex
having iridium (Ir) as metal, and is superior in contribution to a
high quantum yield in light luminous.
[0090] The alkyl group represented by each of R.sub.3', R.sub.3,
R.sub.4 and R.sub.6 may have a substituent and may be a saturated
or unsaturated one. Examples of the substituent the alkyl group may
have include those recited below as the substituent Z. The alkyl
group represented by each of the above R and R' is an alkyl group
which is preferably from 1 to 8, far preferably from 1 to 6, in the
total number of carbon atoms, with examples including a methyl
group, an ethyl group, an i-propyl group, a cyclohexyl group and a
t-butyl group.
[0091] The heteroalkyl group represented by R3' may be a group
formed by substituting O, NR or S for at least one carbon atom in
any of the alkyl groups as recited above.
[0092] The aryl group represented by each of R.sub.3', R, R' and
R.sub.3 to R.sub.4 is preferably a substituted or unsubstituted
aryl group which is from 6 to 30 in the number of carbon atoms,
such as a phenyl group, a tolyl group or a naphthyl group.
[0093] The heteroaryl group represented by each of R.sub.3', R, R'
and R.sub.3 to R.sub.6 is preferably a heteroaryl group which is
from 5 to 8 in the number of carbon atoms, far preferably a
substituted or unsubstituted 5- or 6-membered heteroaryl group,
with examples including a pyridyl group, a pyrazinyl group, a
pyridazinyl group, a pyrimidinyl group, a triazinyl group, a
quinolinyl group, an isoquinolinyl group, a quinazolinyl group, a
cinnolinyl group, a phthalazinyl group, a quinoxalinyl group, a
pyrrolyl group, an indolyl group, a furyl group, a benzofuryl
group, a thienyl group, a benzothienyl group, a pyrazolyl group, an
imidazolyl group, a benzimidazolyl group, a triazolyl group, an
oxazolyl group, an benzoxazolyl group, a thiazolyl group, a
benzothiazolyl group, an isothiazolyl group, a benzisothiazolyl
group, a thiadiazolyl group, an isoxazolyl group, a benzisoxazolyl
group, a pyrrolidinyl group, a piperidinyl group, a piperazinyl
group, an imidazolidinyl group, a thiazolinyl group and a
sulfolanyl group.
[0094] Examples of the heteroaryl group represented by R.sub.3' are
preferably a pyridyl group, a pyrimidinyl group, an imidazolyl
group and a thienyl group, far preferably a pyridyl group and a
pyrimidinyl group.
[0095] Groups preferred as R.sub.3' include a methyl group, an
ethyl group, a propyl group and a butyl group. Of these groups, a
methyl group and an ethyl group are far preferred, and a methyl
group is further preferred.
[0096] R.sub.5 represents an aryl group or a heteroaryl group, and
at least one hydrogen atom of the aryl or heteroaryl group may be
replaced with a nonaromatic group.
[0097] The nonaromatic group in R.sub.5 is preferably an alkyl
group, an alkoxy group, a fluoro radical, a cyano group, an
alkylamino group or a diarylamino group, far preferably an alkyl
group, a fluoro group or a cyano group, further preferably an alkyl
group.
[0098] Groups preferred as R.sub.5 are a phenyl group, a p-tolyl
group and a naphthyl group. Of these groups, a phenyl group is far
preferable.
[0099] It is preferable that each of R.sub.3, R.sub.4 and R.sub.6
represent a hydrogen atom, an alkyl group, a cyano group, a
trifluoromethyl group, a perfluoroalkyl group, a dialkylamino
group, a fluoro group, an aryl group or a heteroaryl group. Of
these group, a hydrogen atom, an alkyl group, a cyano group, a
trifluoromethyl group, a fluoro group and an aryl group are far
preferably, and a hydrogen atom, an alkyl group and an aryl group
are further preferable.
[0100] The substituent Z in each of R.sub.3, R.sub.4 and R.sub.6 is
preferably an alkyl group, an alkoxy group, a fluoro group, a cyano
group or a dialkylamino group. It is far preferable that each of
R.sub.3, R.sub.4 and R.sub.6 has no substituent Z.
[0101] Examples of an aromatic heterocyclic ring which the ring Q
represents include a pyridine ring, a pyrazine ring, a pyrimidine
ring, a pyrazole ring, an imidazole ring, a triazole ring, an
oxazole ring, an oxadiazole ring, a thiazole ring and a thiadiazole
ring. Of these rings, a pyridine ring and a pyrazine ring are
preferable, and a pyridine ring is far preferable.
[0102] Examples of a condensed aromatic heterocyclic ring which the
ring Q represents include a quinoline ring, an isoquinoline ring,
and a quinoxaline ring. Of these rings, a quinoline ring and an
isoquinoline ring are preferable, and a quinoline ring is far
preferable.
[0103] The nonaromatic group which the ring Q may have as a
substituent is preferably an alkyl group, an alkoxy group, a fluoro
group, a cyano group, an alkylamino group or a diarylamino group,
far preferably an alkyl group, a fluoro group or a cyano group.
[0104] m represents an integer from 1 to 3, preferably 2 or 3, far
preferably 2.
[0105] n represents an integer from 0 to 2, preferably 0 or 1, far
preferably 1.
[0106] And it is further preferable that m represents 2 and n
represents 1.
[0107] (X--Y) represents an ancillary ligand. It is thought that
such a ligand has no direct contribution to photoactive properties
but can make modifications to photoactive properties of molecules.
Such a ligand is therefore referred to as an "ancillary" ligand.
Definitions of "photoactive" and "ancillary" given to the ligand
are aimed at a nonattributive theory. For instance, as to the
bidentate ligand in the case of Ir, n may stand for 0, 1 or 2.
Ancillary ligands usable in light emitting materials can be
selected from those heretofore known in the field. Examples of
nonattributive use of bidentate ligands are described in Lamansky
et al., PCT application WO-A1-0215645, pp. 89-90, which is cited as
a reference. Suitable examples of an ancillary ligand include
acetylacetonate (acac), picolinate (pic) and their derivatives. The
ancillary ligand preferred in the invention is acetylacetonate from
the viewpoint of achieving complex stability and high luminous
efficiency.
##STR00032##
[0108] The compound represented by the formula (T-1) is preferably
a compound represented by the following formula (T-2).
##STR00033##
[0109] In the formula (T-2), R.sub.3' represents an alkyl group, a
heteroalkyl group, an aryl group or a heteroaryl group, which each
may further have a substituent Z.
[0110] Each of R.sub.4' to R.sub.6' independently represents a
hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group,
a heteroalkyl group, an aryl group or a heteroaryl group, which
each may further have a substituent Z.
[0111] Alternatively, R.sub.3' and R.sub.4', or R.sub.4' and
R.sub.5', or R.sub.5' and R.sub.6' may combine with each other to
complete a condensed 4- to 7-membered ring, and the condensed 4- to
7-membered ring is a cycloalkane ring, a cycloheteroalkane ring, an
arene ring or a heteroarene ring, which each may further have a
substituent Z.
[0112] R.sub.3' and R.sub.6 may complete a ring by linking via a
linking group selected from the groups consisting of
--CR.sub.2--CR.sub.2--, --CR.dbd.CR--, --CR.sub.2--, --O--, --NR--,
--O--CR.sub.2--, --NR--CR.sub.2-- and --N.dbd.CR--, each of the Rs
independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, a heteroalkyl group, an aryl group
or a heteroaryl group, which each may further have a substituent
Z.
[0113] R.sub.5 represents an aryl group or a heteroaryl group,
which each may further have a nonaromatic group.
[0114] Each of R.sub.3, R.sub.4 and R.sub.6 independently
represents a hydrogen atom, an alkyl group, an alkenyl group, an
alkynyl group, --CN, --CF.sub.3, --C.sub.nF.sub.2n+1, a
trifluorovinyl group, --CO.sub.2R, --C(O)R, --NR.sub.2, --NO.sub.2,
--OR, a halogen atom, an aryl group or a heteroaryl group, which
each may further have a substituent Z.
[0115] Alternatively, R.sub.3 and R.sub.4 may combine with each
other to complete a condensed 4- to 7-membered ring, and the
condensed 4- to 7-membered ring is a cycloalkane ring, a
cycloheteroalkane ring, an arene ring or a heteroarene ring, which
each may further have a substituent Z.
[0116] Each of Zs independently represents a halogen atom, --R',
--OR', --N(R').sub.2, --SR', --C(O)R', --C(O)OR',
--C(O)N(R').sub.2, --CN, --NO.sub.2, --SO.sub.2, --SOR',
--SO.sub.2R' or --SO.sub.3R', and each of R's independently
represents a hydrogen atom, an alkyl group, a perhaloalkyl group,
an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl
group or a heteroaryl group.
[0117] (X--Y) represents an ancillary ligand.
[0118] m represents an integer from 1 to 3 and n represents an
integer from 0 to 2, provided that m+n=3.
[0119] R.sub.3', R.sub.3 to R.sub.6, (X--Y), m and n in the formula
(T-2) have the same meanings as R.sub.3', R.sub.3 to R.sub.6,
(X--Y), m and n in the formula (T-1), respectively, and they are
also alike in their respective preferences.
[0120] R.sub.4' preferably represents a hydrogen atom, an alkyl
group, an aryl group or a fluoro group, and far preferably
represents a hydrogen atom.
[0121] R.sub.5' and R.sub.6' preferably represent hydrogen atoms or
combine with each other to complete a condensed 4- to 7-membered
ring, and the condensed 4- to 7-membered ring is preferably a
cycloalkane ring, a cycloheteroalkane ring, an arene ring or a
heteroarene ring, far preferably an arene ring.
[0122] When each of those represented by R.sub.4' to R.sub.6' can
have a substituent Z, the substituent Z is preferably an alkyl
group, an alkoxy group, a fluoro group, a cyano group, an
alkylamino group or a diarylamino group, far preferably an alkyl
group.
[0123] The compound represented by the formula (T-2) is preferably
a compound represented by the following formula (T-3).
##STR00034##
[0124] In the formula (T-3), R.sub.4' represents a hydrogen atom,
an alkyl group, an alkenyl group, an alkynyl group, a heteroalkyl
group, an aryl group or a heteroacryl group, which each may further
have a substituent Z.
[0125] R.sub.5'' and R.sub.6'' represent hydrogen atoms or combine
with each other to complete a condensed 4- to 7-membered ring, and
the condensed 4- to 7-membered ring is a cycloalkane ring, a
cycloheteroalkane ring, an arene ring or a heteroarene ring.
[0126] Each of R.sub.3, R.sub.4 and R.sub.6 independently
represents a hydrogen atom, an alkyl group, an alkenyl group, an
alkynyl group, --CN, --CF.sub.3, C.sub.nF.sub.2n+1, a
trifluorovinyl group, --CO.sub.2R, --C(O)R, --NR.sub.2, --NO.sub.2,
--OR, a halogen atom, an aryl group or a heteroaryl group, which
each may further have a substituent Z.
[0127] Alternatively, R.sub.3 and R.sub.4 may combine with each
other to form a condensed 4- to 7-membered ring, and the condensed
4- to 7-membered ring is a cycloalkane ring, a cycloheteroalkane
ring, an arene ring or a heteroarene ring, which each may have a
substituent Z.
[0128] Each of Zs independently represents a halogen atom, --R',
--OR', --N(R').sub.2, --SR', --C(O)R', --C(O)OR',
--C(O)N(R').sub.2, --CN, --NO.sub.2, --SO.sub.2, --SOR',
--SO.sub.2R' or --SO.sub.3R', and each of R's independently
represents a hydrogen atom, an alkyl group, a perhaloalkyl group,
an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl
group or a heteroaryl group.
[0129] (X--Y) represents an ancillary ligand.
[0130] m represents an integer from 1 to 3 and n represents an
integer from 0 to 2, provided that m+n=3.
[0131] R.sub.4', R.sub.3, R.sub.4, R.sub.6, (X--Y), m and n in the
formula (T-3) have the same meanings as R.sub.4', R.sub.3, R.sub.4,
R.sub.6, (X--Y), m and n in the formula (T-2), respectively, and
they are also alike in their respective preferences.
[0132] It is preferable that each of R.sub.5'' and R.sub.6''
represents a hydrogen atom or R.sub.5'' and R.sub.6'' are combined
together to complete an arene ring, and it is further preferred
that R.sub.5'' and R.sub.6'' are combined together to complete an
arene ring.
[0133] The compound represented by the formula (T-3) is preferably
a compound represented by the following formula (T-4).
##STR00035##
[0134] In the formula (T-4), each of R.sub.3, R.sub.4 and R.sub.6
independently represents a hydrogen atom, an alkyl group, an
alkenyl group, an alkynyl group, --CN, --CF.sub.3,
--C.sub.nF.sub.2n+1, a trifluorovinyl group, --CO.sub.2R, --C(O)R,
--NR.sub.2, --NO.sub.2, --OR, a halogen atom, an aryl group or a
heteroaryl group, which each may further have a substituent Z.
[0135] Each of Zs independently represents a halogen atom, --R',
--OR', --N(R').sub.2, --SR', --C(O)R', --C(O)OR',
--C(O)N(R').sub.2, --CN, --NO.sub.2, --SO.sub.2, --SOR',
--SO.sub.2R' or --SO.sub.3R', and each of R's independently
represents a hydrogen atom, an alkyl group, a perhaloalkyl group,
an alkenyl group, an alkynyl group, a heteroalkyl group, an aryl
group or a heteroaryl group.
[0136] (X--Y) represents an ancillary ligand.
[0137] m represents an integer from 1 to 3 and n represents an
integer from 0 to 2, provided that m+n=3.
[0138] R.sub.3, R.sub.4, R.sub.6, (X--Y), m and n in the formula
(T-4) have the same meanings as R.sub.3, R.sub.4, R.sub.6, (X--Y),
m and n in the formula (T-1), respectively, and they are also alike
in their respective preferences.
[0139] Examples of the compound represented by the formula (T-1)
are illustrated below, but the invention should not be construed as
being limited to these examples.
##STR00036## ##STR00037## ##STR00038## ##STR00039## ##STR00040##
##STR00041## ##STR00042## ##STR00043## ##STR00044##
##STR00045##
[0140] The compounds illustrated above as examples of the compound
represented by the formula (T-1) can be synthesized according to
various methods as disclosed in JP-A-2009-99783 and U.S. Pat. No.
7,279,232. For instance, Exemplified Compound TM-1 can be
synthesized by using 2-chloro-3-methylquinoline as a starting
material in accordance with the method disclosed in U.S. Pat. No.
7,279,232, column 21, line 1, to column 27, line 33. And
Exemplified Compound TM-2 can be synthesized by using
2-bromo-3-methylpyridine in accordance with the method disclosed in
U.S. Pat. No. 7,279,232, column 29, line 1, to column 31, line
29.
[0141] In the invention, though the compound represented by the
formula (T-1) is incorporated into a light emitting layer, there is
no limitation to its usage but the compound may further be
incorporated into any layer among organic layers.
[0142] In the invention, both the compound of the formula (T-1) and
the compound of the formula (1) are incorporated into a light
emitting layer in order to minimize shifts in chromaticity under
high-temperature drive.
[0143] When the compound represented by the formula (T-1) is
incorporated into a light emitting layer, the compound content is
preferably from 0.1% to 30% by mass, far preferably from 1% to 20%
by mass, further preferably from 5% to 15% by mass, with respect to
the total mass of the light emitting layer.
<Composition Containing Compound of Formula (1) and Compound of
Formula (T-1)>
[0144] The invention also relates to a composition containing the
compound represented by the formula (1) and the compound
represented by the formula (T-1).
[0145] The content of the compound represented by the formula (1)
in the composition is preferably from 50% to 99% by mass, far
preferably from 70% to 95% by mass.
[0146] The content of the compound represented by the formula (T-1)
in the composition is preferably from 1% to 30% by mass, far
preferably from 5% to 15% by mass.
[0147] Other ingredients which the composition can contain may be
organic substances or inorganic substances. What can be used as the
organic substances are materials recited below as a host material,
a fluorescent material, a phosphorescent material and a hydrocarbon
material, preferably a host material and a hydrocarbon material,
far preferably a compounds represented by the formula (VI)
illustrated hereinafter.
[0148] The composition according to the invention can form an
organic layer for the organic electroluminescence device by using
e.g. a dry film-making method, such as a vapor deposition method or
a sputtering method, a transfer method or a printing method.
<Organic Electroluminescence Device>
[0149] The present devices are described below in detail.
[0150] The present electroluminescence device has a first electrode
and a second electrode each on a substrate and a light emitting
layer sandwiched between the first electrode and the second
electrode. In addition, the light emitting layer contains the
compound represented by the formula (1) and the compound
represented by the formula (T-1).
[0151] In the present organic electroluminescence devices, the
light emitting layer is an organic layer, and two or more organic
layers may further be included.
[0152] In terms of properties of the luminescence device, it is
preferred that at least either of the two electrodes, an anode and
a cathode, be transparent or translucent.
[0153] FIG. 1 shows one example of structures of the present
organic electroluminescence devices. The present organic
electroluminescence device 10 shown in FIG. 1 has, on a supporting
substrate 2, a light emitting layer 6 sandwiched between an anode 3
and a cathode 9. More specifically, between an anode 3 and a
cathode 9, a hole injection layer 4, a hole transport layer 5, a
light emitting layer 6, a hole block layer 7 and an electron
transport layer 8 are stacked on in the order of mention.
<Structure of Organic Layer>
[0154] The organic layer has no particular restriction on its layer
structure, and the layer structure thereof can be selected
appropriately according to purposes of using the organic
electroluminescence device. However, it is preferred that the
organic layer be formed on the transparent electrode or the back
electrode. In such a case, the organic layer is formed on the front
of or all over the transparent electrode or the back electrode.
[0155] The organic layer has no particular limitations e.g. on its
shape, size and thickness, and these factors can be selected as
appropriate according to purposes given to the organic layer.
[0156] The following are specific examples of a layer structure,
but these layer structures should not be construed as limiting the
scope of the invention. [0157] Anode/hole transporting layer/light
emitting layer/electron transporting layer/cathode [0158]
Anode/hole transporting layer/light emitting layer/blocking
layer/electron transporting layer/cathode [0159] Anode/hole
transporting layer/light emitting layer/blocking layer/electron
transporting layer/electron injection layer/cathode [0160]
Anode/hole injection layer/hole transporting layer/light emitting
layer/blocking layer/electron transporting layer/cathode [0161]
Anode/hole injection layer/hole transporting layer/light emitting
layer/blocking layer/electron transporting layer/electron injection
layer/cathode
[0162] The structure, substrate, cathode and anode of an organic
electroluminescence device are described e.g. in JP-A-2008-270736,
and the items described in such a reference can also be applied to
the invention.
<Substrate>
[0163] The substrate used in the invention is preferably a
substrate which causes neither scattering nor damping of light
emitted from the organic layer. When the substrate is made from an
organic material, it is preferable that the organic material has
excellent heat resistance, dimensional stability, solvent
resistance, electrical insulation and workability.
<Anode>
[0164] In ordinary cases, it is essential only that the anode
should function as an electrode for supplying holes into the
organic layer, and there is no particular limitation e.g. on
anode's shape, structure and size. And the electrode material can
be selected from heretofore known ones as appropriate according to
uses and purposes of the luminescence device. As mentioned above,
the anode is usually provided in a state of being transparent.
<Cathode>
[0165] In ordinary cases, it is essential only that the cathode
should function as an electrode for supplying electrons into the
organic layer, and there is no particular limitation e.g. on
anode's shape, structure and size. And the electrode material can
be selected from heretofore known ones as appropriate according to
uses and purposes of the luminescence device.
[0166] With respect to the substrate, the anode and the cathode,
the matters described in JP-A-2008-270736 are applicable in the
invention.
<Organic Layer>
[0167] The organic layer in the invention is explained.
--Formation of Organic Layer--
[0168] Each organic layer in the present organic
electroluminescence device can be suitably formed in accordance
with any of a dry film formation method, such as a vapor deposition
method or a sputtering method, a transfer method, a printing method
and the like.
(Light Emitting Layer)
<Light Emitting Material>
[0169] The light emitting material for use in the invention is
preferably the compound represented by the formula (T-1).
[0170] The light emitting material content in the light emitting
layer is generally from 0.1% to 50% by mass with respect to the
total mass of compounds constituting the light emitting layer, but
from the viewpoints of durability and external quantum efficiency,
the content is preferably from 1% to 50% by mass, far preferably
from 2% to 40% by mass.
[0171] The thickness of the light emitting layer, though not
particularly limited, is preferably from 2 nm to 500 nm in ordinary
cases. From the viewpoint of external quantum efficiency in
particular, the thickness is far preferably from 3 nm to 200 nm,
further preferably from 5 nm to 100 nm.
[0172] The light emitting layer in the present device may be
constituted of only a light emitting material or a mixture of a
light emitting material with a host material. The light emitting
material may be either a fluorescent material or a phosphorescent
material, and one or two or more types of dopant may be added
thereto. The host material is preferably a charge transport
material. One type of host material or two or more types of host
materials may be used. For instance, the host material may be
constituted of a mixture of an electron transporting host material
and a hole transporting host material. Further, the light emitting
layer may contain a material which neither has a charge
transporting property nor emits light. The light emitting layer in
the present device is preferably the light emitting layer which
uses the compound represented by the formula (1) as the host
material and the compound represented by the formula (T-1) as the
light emitting material.
[0173] Additionally, the light emitting layer may be a single
layer, or it may include multiple (two or more) constituent layers.
When the light emitting layer includes multiple constituent layers,
each of two or more constituent layers may contain the compound
represented by the formula (1) and the compound represented by the
formula (T-1). In addition, each of the multiple constituent layers
may emit light different in luminescent color.
[0174] The invention relates also to a light emitting layer
containing the compound represented by the formula (1) and the
compound represented by the formula (T-1). The present light
emitting layer can be used in organic electroluminescence
device.
<Host Material>
[0175] The host material for use in the invention is preferably the
compound represented by the formula (1).
[0176] The compound represented by the formula (1) is a compound
capable of transporting both holes and electrons, by using the
compound represented by the formula (1) in combination with the
compound represented by the formula (T-2), it is possible to
inhibit the balance between abilities to transport holes and
electrons in the light emitting layer from changing with
temperature, electric field and other external environments. And
thereby the durability under driving can be increased even though
the compound has a carbazolyl group. Moreover, a shift in
chromaticity under high-temperature drive can be inhibited.
[0177] The host material used in the invention may further contain
the following compounds. Examples thereof include pyrrole, indole,
carbazole (including CBP (4,4'-di(9-carbazolyl)biphenyl)),
azaindole, azacarbazole, triazole, oxazole, oxadiazole, pyrazole,
imidazole, thiophene, polyarylalkane, pyrazoline, pyrazolone,
phenylenediamine, arylamine, amino-substituted chalcone,
styrylanthracene, fluorenone, hydrazone, stilbene, silazane,
aromatic tertiary amine compounds, styrylamine compounds; porphyrin
compounds, polysilane compounds, poly(N-vinylcarbazole), aniline
copolymers, thiophene oligomers, oligomers of conductive polymers
like polythiophene, organic silanes, carbon film, pyridine,
pyrimidine, triazine, anthraquinodimethane, anthrone,
diphenylquinone, thiopyran dioxide, carbodiimide,
fluorelenylidenemethane, distyrylpyrazine, fluoro-substituted
aromatic compounds, tetracarboxylic acid anhydrides of condensed
aromatic ring compounds such as naphthalene and perylene,
phthalocyanine, various kinds of metal complexes, typified by metal
complexes of 8-quinolinol derivatives and metal complexes whose
ligands are metallo-phthalocyanines, benzoxazole or benzothiazole
molecules, and derivatives of the above-recited metal complexes
(e.g. those replaced with substituents or those condensed with
other rings).
[0178] In the light emitting layer according to the invention, it
is preferable that the lowest triplet-state excitation energy
(T.sub.1 energy) of the host materials (including the compounds
represented by the formula (1)) is higher than T.sub.1 energy of
the phosphorescent materials in terms of color purity, luminous
efficiency and durability under driving.
[0179] The host-compound content in the invention is not
particularly limited, but in terms of luminous efficiency and drive
voltage it is preferably from 15% to 98% by mass with respect to
the total mass of all compounds constituting the light emitting
layer. The compound represented by the formula (1) preferably
constitutes from 30% to 98% by mass of all host compounds.
[0180] When the compound represented by the formula (1) is
introduced into a layer other than the light emitting layer (e.g. a
charge transport layer), the content thereof in the layer is
preferably from 10% to 100% by mass, far preferably from 30% to
100% by mass.
(Fluorescent Material)
[0181] Examples of a fluorescent material usable in the invention
include benzoxazole derivatives, benzimidazole derivatives,
benzothiazole derivatives, styrylbenzene derivatives, polyphenyl
derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene
derivatives, naphthalimide derivatives, coumarin derivatives,
condensed aromatic compounds, perinone derivatives, oxadiazole
derivatives, oxazine derivatives, aldazine derivatives, pyralidine
derivatives, cyclopentadiene derivatives, bisstyrylanthracene
derivatives, quinacridone derivatives, pyrrolopyridine derivatives,
thiadiazolopyridine derivatives, cyclopentadiene derivatives,
styrylamine derivatives, diketopyrrolopyrrole derivatives, aromatic
dimethylidyne derivatives, various kinds of complexes typified by
complexes of 8-quinolinol derivatives and complexes of pyrromethene
derivatives, polymeric compounds such as polythiophene,
polyphenylene and polyphenylenevinylene, and compounds like organic
silane derivatives.
(Phosphorescent Material)
[0182] Examples of a phosphorescent material usable in the
invention include the compounds represented by the formula (T-1),
and besides, they include the phosphorescent compounds as disclosed
in U.S. Pat. No. 6,303,238B1, U.S. Pat. No. 6,097,147, WO 00/57676,
WO 00/70655, WO 01/08230, WO 01/39234A2, WO 01/41512A1, WO
02/02714A2, WO 02/15645A1, WO 02/44189A1, WO 05/19373A2,
JP-A-2001-247859, JP-A-2002-302671, JP-A-2002-117978,
JP-A-2003-133074, JP-A-2002-235076, JP-A-2003-123982,
JP-A-2002-170684, EP 1211257, JP-A-2002-226495, JP-A-2002-234894,
JP-A-2001-247859, JP-A-2001-298470, JP-A-2002-173674,
JP-A-2002-203678, JP-A-2002-203679, JP-A-2004-357791,
JP-A-2006-256999, JP-A-2007-19462, JP-A-2007-84635 and
JP-A-2007-96259. Examples of luminescent dopants which are far
preferred among those compounds include the Ir complexes, the Pt
complexes, the Cu complexes, the Re complexes, the W complexes, the
Rh complexes, the Ru complexes, the Pd complexes, the Os complexes,
the Eu complexes, the Tb complexes, the Gd complexes, the Dy
complexes and the Ce complexes. Of these complexes, Ir complexes,
the Pt complexes and the Re complexes are particularly preferable,
notably Ir complexes, the Pt complexes and the Re complexes each
having at least one kind of coordination bond selected from
metal-carbon, metal-nitrogen, metal-oxygen and metal-sulfur
coordinate bonds. In terms of luminous efficiency, durability under
driving, chromaticity and so on, the Ir complexes, the Pt complexes
and the Re complexes each having a polydentate ligand, including a
tridentate ligand or higher, are preferred over the others.
[0183] The content of phosphorescent materials in the light
emitting layer is preferably in a range from 0.1% to 50% by mass,
far preferably from 0.2% to 50% by mass, further preferably from
0.3% to 40% by mass, especially preferably from 20% to 30% by mass,
with respect to the total mass of the light emitting layer.
[0184] The content of phosphorescent materials usable in the
invention (the compounds represented by the formula (T-1) and/or
phosphorescent materials used in combination therewith) is
preferably in a range from 0.1% to 50% by mass, far preferably from
1% to 40% by mass, especially preferably from 5% to 30% by mass,
with respect to the total mass of the light emitting layer. In the
range from 5% to 30% by mass in particular, luminescence
chromaticity of the organic electroluminescence device has small
dependence on the concentration of added phosphorescent
materials.
[0185] It is the best for the present organic electroluminescence
device to incorporate at least one of the compounds represented by
the formula (T-1) in an amount of 5% to 30% by mass with respect to
the total mass of the light emitting layer.
[0186] The organic electroluminescence devices preferably contain a
hydrocarbon compound, notably in their respective light emitting
layers.
[0187] And the hydrocarbon compound is preferably a compound
represented by the following formula (VI).
[0188] The proper use of the compound represented by the formula
(VI) in combination with the light emitting materials makes it
possible to appropriately control interactions between molecules of
the material and to render energy-gap interaction between
neighboring molecules uniform, thereby allowing further reduction
in drive voltage.
[0189] Moreover, the compound which is represented by the formula
(VI) and usable in organic electroluminescence devices has
excellent chemical stability, and slightly causes degradation, such
as decomposition, in materials under driving of the devices, and
therefore the organic electroluminescence devices containing the
compound of the formula (VI) can avoid reduction in their
efficiency and lifespan through decomposition of the materials.
[0190] The compound represented by the formula (VI) is explained
below.
##STR00046##
[0191] In the formula (VI), each of R.sub.4, R.sub.6, R.sub.8,
R.sub.10 and X.sub.4 to X.sub.15 independently represents a
hydrogen atom, an alkyl group or an aryl group.
[0192] The alkyl group represented by each of R.sub.4, R.sub.6,
R.sub.8, R.sub.10 and X.sub.4 to X.sub.15 in the formula (VI) may
have as a substituent an adamantane structure or an aryl structure,
and the number of carbon atoms in the alkyl group is preferably
from 1 to 70, far preferably from 1 to 50, further preferably from
1 to 30, still further preferably from 1 to 10, especially
preferably from 1 to 6. And the most preferable alkyl groups are
linear alkyl groups having 2 to 6 carbon atoms.
[0193] Examples of the alkyl group represented by each of R.sub.4,
R.sub.6, R.sub.8, R.sub.10 and X.sub.4 to X.sub.15 in the formula
(VI) include an n-C.sub.50H.sub.101 group, an n-C.sub.30H.sub.61
group, 3-(3,5,7-triphenyladamantane-1-yl)propyl group (number of
carbon atoms: 31), a trityl group (number of carbon atoms: 19),
3-(adamantane-1-yl)propyl group (number of carbon atoms: 13),
9-decalyl group (number of carbon atoms: 10), a benzyl group
(number of carbon atoms: 7), a cyclohexyl group (number of carbon
atoms: 6), a n-hexyl group (number of carbon atoms: 6), an n-pentyl
group (number of carbon atoms: 5), an n-butyl group (number of
carbon atoms: 4), an n-propyl group (number of carbon atoms: 3), a
cyclopropyl group (number of carbon atoms: 3), an ethyl group
(number of carbon atoms: 2) and a methyl group (number of carbon
atoms: 1).
[0194] The aryl group represented by each of R.sub.4, R.sub.6,
R.sub.8, R.sub.10 and X.sub.4 to X.sub.15 in the formula (VI) may
have as a substituent an adamantane structure or an alkyl
structure, and the number of carbon atoms the aryl group has is
preferably from 6 to 30, far preferably from 6 to 20, further
preferably from 6 to 15, especially preferably from 6 to 10, the
most preferably is 6.
[0195] Examples of the aryl group represented by each of R.sub.4,
R.sub.6, R.sub.8, R.sub.10 and X.sub.4 to X.sub.15 in the formula
(VI) include a 1-pyrenyl group (number of carbon atoms: 16), a
9-anthracenyl group (number of carbon atoms: 14), a 1-naphthyl
group (number of carbon atoms: 10), a 2-naphthyl group (number of
carbon atom: 10), a p-t-butylphenyl group (number of carbon atoms:
10), a 2-m-xylyl group (number of carbon atoms: 8), a 5-m-xylyl
group (number of carbon atoms: 8), an o-tolyl group (number of
carbon atoms: 7), a m-tolyl group (number of carbon atoms: 7), a
p-tolyl group (number of carbon atoms: 7) and a phenyl group
(number of carbon atoms: 6).
[0196] Although each of R.sub.4, R.sub.6, R.sub.8 and R.sub.10 in
the formula (VI) may be either a hydrogen atom, or an alkyl group,
or an aryl group, from the viewpoint that high glass transition
temperatures are preferable, it is preferable that at least one of
them is an aryl group, it is far preferable that at least two of
them are aryl groups, and it is particularly preferable that 3 or 4
of them are aryl groups.
[0197] Although each of X.sub.4 to X.sub.15 in the formula (VI) may
be either a hydrogen atom, or an alkyl group, or an aryl group, it
is preferable that each are a hydrogen atom or an aryl group,
especially a hydrogen atom.
[0198] The organic electroluminescence devices are made using a
vacuum deposition process or a solution coating process, and
therefore, in terms of vacuum deposition suitability and
solubility, the molecular weight of the compounds represented by
the formula (VI) in the invention is preferably 2,000 or below, far
preferably 1,200 or below, especially 1,000 or below. Also, from
the viewpoint of vacuum deposition suitability, the molecular
weight is preferably 250 or above, far preferably 350 or above,
particularly preferably 400 or above. This is because, when the
compounds have too low molecular weight, their vapor pressure
becomes low and change from a vapor phase to a solid phase does not
occur, and it is therefore difficult for the compounds to form
organic layers.
[0199] The compound represented by the formula (VI) is preferably
in solid phase at room temperature (25.degree. C.), far preferably
solid phase in a range from room temperature to 40.degree. C.,
especially preferably solid phase in a range from room temperature
to 60.degree. C.
[0200] In the case of using the compound which, though represented
by the formula (VI), is not in solid phase at room temperature, it
is possible to form a solid phase at ordinary temperatures by
combining the compound with other substances.
[0201] Uses of the compound represented by the formula (VI) are not
limited, and the compound may be incorporated into any of the
organic layers. The layer into which the compound represented by
the formula (VI) in the invention is introduced is preferably a
layer selected from a light emitting layer, a hole injection layer,
a hole transport layer, an electron transport layer, an electron
injection layer, an exciton block layer and a charge block layer,
or a combination of two or more of these layers, far preferably a
layer selected from the light emitting layer, the hole injection
layer, the hole transport layer, the electron transport layer and
the electron injection layer, or a combination of two or more of
these layers, especially preferably a layer selected from the light
emitting layer, the hole injection layer and the hole transport
layer, or a combination of at least two of these layers, the most
preferably the light emitting layer.
[0202] When the compound represented by the formula (VI) is used in
an organic layer, its content is required to be limited so as not
to inhibit charge transportability, and therefore it is preferable
from 0.1% to 70% by mass, far preferable from 0.1% to 30% by mass,
especially preferable from 0.1% to 25% by mass.
[0203] When the compound represented by the formula (VI) is used in
two or more organic layers, its content in each organic layer is
preferably in the range specified above.
[0204] Into any one of the organic layers, only one among the
compounds represented by the formula (VI) may be incorporated, or
any two or more of the compounds represented by the formula (VI)
may be combined in arbitrary proportions and incorporated.
[0205] Examples of the hydrocarbon compound are illustrated below,
but the invention should not be construed as being limited to these
examples.
##STR00047## ##STR00048## ##STR00049## ##STR00050## ##STR00051##
##STR00052## ##STR00053## ##STR00054## ##STR00055## ##STR00056##
##STR00057## ##STR00058##
[0206] The compound represented by the formula (VI) can be
synthesized by appropriately combining adamantane or haloadamantane
with haloalkane or alkylmagnesium halide (Grignard reagent). For
instance, it is possible to provide coupling between haloadamantane
and haloalkane by use of indium (Reference 1). Alternatively, it is
possible to convert haloalkane into an alkylcopper reagent and
further to couple the reagent to Grignard reagent of an aromatic
compound (Reference 2). Further, the coupling of haloalkane can
also be performed using an appropriate arylboric acid and a
palladium catalyst (Reference 3). [0207] Reference 1: Tetrahedron
Lett. 39, 1998, 9557-9558 [0208] Reference 2: Tetrahedron Lett. 39,
1998, 2095-2096 [0209] Reference 3: J. Am. Chem. Soc. 124, 2002,
13662-13663
[0210] The adamantane structure having an aryl group can be
synthesized by appropriately combining adamantane or haloadamantane
with the corresponding arene or haloarene.
[0211] Additionally, even when defined substituents undergo changes
under certain synthesis conditions in those production methods or
they are unsuitable for carrying out those methods, the intended
compounds can be produced with ease by adopting e.g. methods for
protecting and deprotecting functional groups (T. W. Greene,
Protective Groups in Organic Synthesis, John Wiley & Sons Inc.
(1981)). Further, it is also possible to change the order of
reaction steps, including a substituent introduction step, as
appropriate, if needed.
[0212] In general the thickness of the light emitting layer, though
not particularly limited, is preferably from 1 nm to 500 nm, far
preferably from 5 nm to 200 nm, further preferably from 10 nm to
100 nm.
--Hole Injection Layer and Hole Transporting Layer--
[0213] The hole injection layer and the hole transporting layer are
layers having functions of receiving holes from an anode or an
anode side and transporting the holes to a cathode side.
--Electron Injection Layer and Electron Transporting Layer--
[0214] The electron injection layer and the electron transporting
layer are layers having functions of receiving electron's from a
cathode or a cathode side and transporting the electrons to an
anode side.
[0215] With respect to the hole injection layer, the hole
transporting layer, the electron injection layer and the electron
transporting layer, the matters described in JP-A-2008-270736,
paragraph numbers to, are applicable in the invention.
--Hole Blocking Layer--
[0216] The hole blocking layer is a layer having a function of
blocking the holes transported from an anode side to the light
emitting layer from passing on through to the cathode side. In the
invention, the hole blocking layer can be provided as an organic
layer adjacent to the light emitting layer in the cathode side.
[0217] Examples of an organic compound which forms the hole
blocking layer include aluminum complexes such as aluminum(III)
bis(2-methyl-8-quinolinato) 4-phenylphenolate (abbreviated to
BAlq), triazole derivatives, and phenanthroline derivatives such as
2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (abbreviated to
BCP).
[0218] The thickness of the hole blocking layer is preferably from
1 nm to 500 nm, far preferably from 5 nm to 200 nm, further
preferably from 10 nm to 100 nm.
[0219] The hole blocking layer may have either a single-layer
structure made up of one or more than one material as recited above
or a multiple-layer structure made up of two or more layers which
are identical or different in composition.
--Electron Blocking Layer--
[0220] The electron blocking layer is a layer having a function of
preventing the electrons transported from the cathode side to the
light emitting layer from passing through to the anode side. In the
invention, the electron blocking layer can be provided as an
organic layer adjacent to the light emitting layer on the anode
side.
[0221] As the examples of the compounds constituting the electron
blocking layer, for instance, the hole transport materials
described above can be applied.
[0222] The thickness of the electron blocking layer is preferably
from 1 nm to 500 nm, more preferably from 5 nm to 200 nm, still
more preferably from 10 nm to 100 nm. The electron blocking layer
may have a single layer structure composed of one or more of the
above materials or may be a multilayer structure composed of two or
more layers having the same composition or different
compositions.
<Protective Layer>
[0223] In the invention, the whole of the organic EL device may be
coated with a protective layer.
[0224] With respect to the protective layer, the matters described
in JP-A-2008-270736, paragraph numbers to, are applicable in the
invention.
<Sealing Enclosure>
[0225] The present devices may be sealed in their entirety through
the use of sealing enclosure.
[0226] With respect to the sealing enclosure, the matters described
in JP-A-2008-270736, paragraph number, are applicable in the
invention.
<Film Formation Method>
[0227] The invention relates to a film formation method further,
wherein the compound represented by the formula (1) and the
compound represented by the formula (T-1) are made to sublime at
the same time by heating and formed into film.
[0228] At the time of film formation, it is preferable that both of
the compounds are mixed together, or a composition according to the
invention may be used. As to the proportions of the compound
represented by the formula (1) and the compound represented by the
formula (T-1) which are contained in the mixture or the
composition, the compound represented by the formula (T-1) is
preferably from 1% to 45%, far preferably from 1% to 25%, with
respect to the compound represented by the formula (1).
[0229] The heating temperature is preferably from 200.degree. C. to
400.degree. C., far preferably from 250.degree. C. to 320.degree.
C.
[0230] The heating time is preferably from 0.1 hour to 350 hours,
far preferably from 0.1 hour to 150 hours.
[0231] The film formation method according to the invention has the
advantage that film for the light emitting layer having high
efficiency, high durability and a slight color shift under
high-temperature drive can be formed with ease.
(Driving)
[0232] The present organic electroluminescence devices each can
produce luminescence when direct-current (which may include an
alternating current component as required) voltage (ranging usually
from 2 to 15 volts) or direct current is applied between the anode
and the cathode.
[0233] To a driving method for the present organic
electroluminescence devices, the driving methods as disclosed in
JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558,
JP-A-8-234685, JP-A-8-241047, Japanese Patent No. 2784615, U.S.
Pat. Nos. 5,828,429 and 6,023,308 can be applied.
[0234] The present organic electroluminescence devices can be
heightened in light extraction efficiency by utilizing various
publicly-known improvements. For instance, it is possible to
improve light extraction efficiency and increase external quantum
efficiency by working on the substrate's surface profile (e.g.
forming a pattern of microscopic asperities on the substrate's
surface), or by controlling refractive indices of the substrate,
the ITO layer and the organic layers, or by controlling thicknesses
of the substrate, the ITO layer and the organic layers, or so
on.
[0235] The present luminescence devices may adopt a mode of
extracting luminescence from the anode side, or the so-called top
luminous mode.
[0236] The present organic EL devices may have resonator structure.
For instance, each device has on a transparent substrate a
multilayer film mirror made up of a plurality of laminated films
that have different refractive indices, a transparent or
translucent electrode, a light emitting layer and a metal electrode
which are superposed on top of each other. Reflections of light
produced in the light emitting layer occur repeatedly between the
multilayer film mirror and the metal electrode which function as
reflector plates, thereby producing resonance.
[0237] In another aspect, the transparent or translucent electrode
and the metal electrode function as reflector plates, respectively,
on the transparent substrate, and reflections of light produced in
the light emitting layer occur repeatedly between the reflector
plates, thereby producing resonance.
[0238] In order to form a resonance structure, the optical distance
determined from effective refractive indices of the two reflector
plates, and refractive indices and thicknesses of each layers
sandwiched between the two reflector plates are adjusted to have
optimum values for achieving the desired resonance wavelength. The
calculating formula in the first aspect case is described in
JP-A-9-180883, and that in the second aspect case is described in
JP-A-2004-127795.
(Use of Present Luminescence Device)
[0239] The present luminescence devices can be used suitably for
light luminous apparatus, pixels, indication devices, displays,
backlights, electrophotographic devices, illumination light
sources, recording light sources, exposure light sources, readout
light sources, sign, billboards, interior decorations or optical
communications, especially preferably for devices driven in a
region of high-intensity luminescence, such as illumination
apparatus and display apparatus.
[0240] Next the present light luminous apparatus is explained by
reference to FIG. 2.
[0241] The present light luminous apparatus incorporates any one of
the present organic electroluminescence devices.
[0242] FIG. 2 is a cross-sectional diagram schematically showing
one example of the present light luminous apparatus.
[0243] The light luminous apparatus 20 in FIG. 2 includes a
transparent substrate 2 (supporting substrate), an organic
electroluminescence device 10, a sealing enclosure 16 and so
on.
[0244] The organic electroluminescence device 10 is formed by
stacking on the substrate 2 an anode 3 (first electrode), an
organic layer 11 and a cathode 9 (second electrode) in the order of
mention. In addition, a protective layer 12 is superposed on the
cathode 9, and on the protective layer 12 a sealing enclosure 16 is
further provided via an adhesive layer 14. Incidentally, part of
each of the electrodes 3 and 9, a diaphragm and an insulating layer
are omitted in FIG. 2.
[0245] Herein, a light cure adhesive such as epoxy resin, or a
thermosetting adhesive can be used for the adhesive layer 14.
Alternatively, a thermosetting adhesive sheet may be used as the
adhesive layer 14.
[0246] The present light luminous apparatus has no particular
restrictions as to its uses, and specifically, it can be utilized
e.g. as not only illumination apparatus but also display apparatus
of a television set, a personal computer, a mobile phone, an
electronic paper or the like.
[0247] Then, illumination apparatus relating to an embodiment of
the invention is explained by reference to FIG. 3.
[0248] FIG. 3 is a cross-sectional diagram schematically showing
one example of the illumination apparatus relating to an embodiment
of the invention.
[0249] As shown in FIG. 3, the illumination apparatus 40 relating
to an embodiment of the invention is equipped with the organic
electroluminescence device 10 and a light scattering member 30.
More specifically, the illumination apparatus 40 is configured to
bring the substrate 2 of the organic electroluminescence device 10
into a contact with the light scattering member 30.
[0250] The light scattering member 30 has no particular restriction
so long as it can scatter light, but a suitable example thereof is
a glass substrate. And fine particles of transparent resin can be
given as a suitable example of fine particles 32. In such
illumination apparatus 40, light emitted from the organic
electroluminescence device 10 enters the light scattering member 30
at the light incidence plane 30A, the entering light is scattered
by the light scattering member, and the light scattered emerges
from the light exit plane 30B as light for illumination.
EXAMPLES
[0251] The invention will now be illustrated in more detail by
reference to the following examples, but these examples should not
be construed as limiting the scope of the invention.
Synthesis Example 1
[0252] Exemplified Compound TM-1 and TM-13 shown hereafter is
synthesized according to the method described in EXAMPLE 1 and
EXAMPLE 13, respectively of U.S. Pat. No. 7,279,232.
Example 1
[0253] An indium tin oxide (ITO) film-coated glass substrate having
an area of 2.5 square centimeters and a thickness of 0.5 mm (made
by GEOMATEC Corporation, surface resistivity: 10 .OMEGA./sq) is
placed in a cleaning vessel and subjected to ultrasonic cleaning in
2-propanol, and the thus cleaned substrate is further subjected to
UV-ozone treatment of 30 minutes. Onto this transparent anode (ITO
film), the following organic layers are evaporated in sequence by
use of a vacuum evaporation method.
First layer: ITO/CuPc (copper phthalocyanine), Thickness: 10 nm
Second layer: NPD
(N,N'-di-.alpha.-naphthyl-N,N'-diphenyl)-benzidine, Thickness: 30
nm Third layer: Dopant (5% by mass), Host material (95% by mass),
Thickness: 30 nm Fourth layer: BAlq, Thickness: 10 nm Fifth layer:
Alq (tris(8-hydroxyquinoline)aluminum complex, Thickness: 40 nm
[0254] Onto this layer, 0.2 nm-thick film of lithium fluoride and
70 nm-thick film of metal aluminum are evaporated in the order of
mention, thereby forming a cathode.
[0255] The laminate thus obtained is placed in a glove box having
undergone argon gas displacement without exposure to the air, and
sealed by means of a sealing can made of stainless steel and a UV
cure adhesive (XNR5516HV, produced by Nagase-Chiba, Ltd.), thereby
providing Device 1 according to the invention.
Examples 2 to 26 and Comparative Examples 1 to 12
[0256] A variety of devices are made in the same manner as in
Example 1, except that the materials the third layer are changed as
shown in Tables 1 to 3.
TABLE-US-00001 TABLE 1 Chromaticity Ingredients in Light Emitting
External Shift after Layer Quantum Drive High-Temperature Host
Material Dopant Efficiency Durability Drive Color Comparative CBP
5% 3.2% 100 (0.01, 0.02) Red Example 1 Ir(btp).sub.2(acac)
Comparative H-1 5% 3.1% 120 (0.01, 0.03) Example 2
Ir(btp).sub.2(acac) Comparative Exemplified 5% 3.4% 110 (0.01,
0.03) Example 3 Compound 4 Ir(btp).sub.2(acac) Comparative CBP 5%
6.7% 145 (<0.005, 0.009) Example 4 TM-1 Comparative H-1 5% 10.7%
400 (0.02, 0.03) Example 5 TM-1 Example 1 Exemplified 5% 12.0% 650
(<0.005, <0.005) Compound 4 TM-1 Example 2 Exemplified 5%
10.4% 480 (<0.005, <0.005) Compound 49 TM-1 Example 3
Exemplified 5% 8.9% 450 (<0.005, <0.005) Compound 68 TM-1
Example 4 Exemplified 5% 10.5% 750 (<0.005, <0.005) Compound
100 TM-1 Example 5 Exemplified 5% 12.4% 580 (<0.005, <0.005)
Compound 101 TM-1 Example 6 Exemplified 5% 11.9% 550 (<0.005,
<0.005) Compound 103 TM-1 Example 7 Exemplified 5% 11.7% 570
(<0.005, <0.005) Compound 38 TM-1 Example 8 Exemplified 5%
13.0% 450 (<0.005, <0.005) Compound 7 TM-1 Example 9
Exemplified 5% 11.3% 540 (<0.005, <0.005) Compound 54 TM-1
Example 10 Exemplified 5% 10.6% 490 (<0.005, <0.005) Compound
100 TM-1 Example 11 Exemplified 5% 11.5% 600 (<0.005, <0.005)
Compound 111 TM-1
TABLE-US-00002 TABLE 2 Chromaticity Ingredients in Light Emitting
External Shift after Layer Quantum Drive High-Temperature Host
Material Dopant Efficiency Durability Drive Color Comparative CBP
5% 6.7% 150 (<0.005, 0.008) Red Example 6 TM-19 Comparative H-1
5% 10.6% 420 (0.02, 0.02) Example 7 TM-19 Example 12 Exemplified 5%
11.5% 630 (<0.005, <0.005) Compound 4 TM-19 Example 13
Exemplified 5% 10.9% 450 (<0.005, <0.005) Compound 49 TM-19
Example 14 Exemplified 5% 9.7% 440 (<0.005, <0.005) Compound
68 TM-19 Example 15 Exemplified 5% 10.5% 610 (<0.005, <0.005)
Compound 4 TM-15 Example 16 Exemplified 5% 10.7% 600 (<0.005,
<0.005) Compound 4 TM-23 Example 17 Exemplified 5% Compound 4
TM-35 10.6% 620 (<0.005, <0.005) Example 18 Exemplified 5%
10.7% 530 (<0.005, <0.005) Compound 4 TM-27
TABLE-US-00003 TABLE 3 Chromaticity Ingredients in Light Emitting
External Shift after Layer Quantum Drive High-Temp. Host Material
Dopant Efficiency Durability Drive Color Comparative CBP 5% 7.9%
300 (0.02, 0.02) Green Example 8 Ir(ppy).sub.2(acac) Comparative
H-1 5% No Impossible Impossible Example 9 Ir(ppy).sub.2(acac)
luminous to evaluate to evaluate of light Comparative Exemplified
5% 14.6% 500 (0.01, 0.02) Example 10 Compound 4 Ir(ppy).sub.2(acac)
Comparative CBP 5% 15.7% 450 (0.02, 0.02) Example 11 TM-2
Comparative H-1 5% No Impossible Impossible Example 12 TM-2
luminous to evaluate to evaluate of light Example 19 Exemplified 5%
18.9% 1,000 (<0.005, <0.005) Compound 4 TM-2 Example 20
Exemplified 5% 15.8% 650 (<0.005, <0.005) Compound 49 TM-2
Example 21 Exemplified 5% 16.4% 690 (<0.005, <0.005) Compound
68 TM-2 Example 22 Exemplified 5% 17.1% 670 (<0.005, <0.005)
Compound 4 TM-8 Example 23 Exemplified 5% 16.5% 660 (<0.005,
<0.005) Compound 4 TM-16 Example 24 Exemplified 5% 15.2% 640
(<0.005, <0.005) Compound 4 TM-38 Example 25 Exemplified 5%
15.3% 690 (<0.005, <0.005) Compound 4 TM-40 Example 26
Exemplified 5% 16.1% 540 (<0.005, <0.005) Compound 4
TM-24
(Performance Evaluation of Organic Electroluminescence Device)
[0257] Performance evaluations of the various devices thus obtained
are conducted.
(a) External Quantum Efficiency
[0258] Each device is made to emit light through the application of
a direct-current voltage by means of Source Measure Unit 2400 made
by TOYO Corporation, and the intensity of the light is measured
with a luminance meter BM-8 made by TOPCON CORPORATION. And the
luminous spectrum and the luminous wavelength are measured with a
Spectral Analyzer PMA-11 made by Hamamatsu Photonics K.K. On the
basis of these data, the external quantum efficiency at a luminance
of about 1,000 cd/m.sup.2 is calculated according to a luminance
conversion method.
(c) Drive Durability
[0259] Each device is made to continue emitting light through the
application of a direct-current voltage to achieve the luminance of
1,000 cd/m.sup.2, and the time required for the luminance to be
reduced to 500 cd/m.sup.2 is taken as an index of drive durability.
In Tables 1 to 3, the drive durability values are shown as relative
values, with the case of Comparative Example 1 being taken as
100.
(d) Chromaticity Shift under High-Temperature Drive
[0260] Differences in x-value and y-value (.DELTA.x, .DELTA.y)
between the chromaticity of light emitted from each device through
the application of a direct-current voltage to achieve the
luminance of 1,000 cd/m.sup.2 (.DELTA.x) and the chromaticity of
light emitted from each device at the time when the luminance is
reduced to 500 cd/m.sup.2 by the device being placed in an
80.degree. C. constant-temperature oven and made to continue
emitting light through the application of a direct-current voltage
to achieve the luminance of 1,000 cd/m.sup.2 (.DELTA.y) are taken
as an index of chromaticity shift under high-temperature drive.
[0261] From the results shown in Tables 1 to 3, it can be seen that
the present devices using carbazolyl-containing host materials
represented by the formula (1) and particular iridium complexes
represented by the formula (T-1) in combination in their respective
light emitting layers are extremely superior in external quantum
efficiency and drive durability to the comparative devices, and
have a smaller color shift after high-temperature drive than the
comparative devices.
[0262] In the cases of light luminous apparatus, display apparatus
and illumination apparatus, it is necessary to instantaneously emit
high-intensity light from every pixel part by the passage of high
current density through each pixel part. The present luminescence
devices are therefore designed to enhance luminous efficiency in
such cases, and thereby they can be used to advantage.
[0263] In addition, the present devices are superior in luminous
efficiency and durability even when used in high-temperature
surroundings as in the case of an in-car use, and therefore they
are suitable for use in light luminous apparatus, display apparatus
and illumination apparatus.
[0264] The structures of the compounds used in Examples and
Comparative Examples are illustrated below.
##STR00059## ##STR00060## ##STR00061## ##STR00062## ##STR00063##
##STR00064## ##STR00065## ##STR00066##
INDUSTRIAL APPLICABILITY
[0265] According to the present invention, an organic
electroluminescence device which has excellent luminescence
characteristics and capable of suppressing a chromaticity shift
under high-temperature drive and excel in luminous efficiency, a
composition and a light emitting layer useful to such an organic
electroluminescence device, a film formation method for the
compound useful to such an organic electroluminescence device, a
light luminous apparatus and an illumination apparatus each
incorporating such an organic electroluminescence device can be
provided.
[0266] This application is based on Japanese patent application
Nos. 2009-180224 filed on Jul. 31, 2009, and 2009-221665 filed on
Sep. 25, 2009, the entire content of which is hereby incorporated
by reference, the same as if set forth at length.
DESCRIPTION OF REFERENCE NUMERALS AND SIGNS
[0267] 2 . . . Substrate [0268] 3 . . . Anode [0269] 4 . . . Hole
injection layer [0270] 5 . . . Hole transporting layer [0271] 6 . .
. Light emitting layer [0272] 7 . . . Hole blocking layer [0273] 8
. . . Electron transporting layer [0274] 9 . . . Cathode [0275] 10
. . . Organic electroluminescence device (Organic EL device) [0276]
11 . . . Organic Layer [0277] 12 . . . Protective Layer [0278] 14 .
. . Adhesive Layer [0279] 16 . . . Sealing enclosure [0280] 20 . .
. Light luminous apparatus [0281] 30 . . . Light scattering member
[0282] 30A . . . Light incidence plane [0283] 30B . . . Light exit
plane [0284] 32 . . . Fine particles [0285] 40 . . . Illumination
apparatus
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